Dynamic SQL questions

I have a table with the following format:

                    
Company timeid  category volume  grossmargin                      
c1000     jan      act     100      1000                      
C1000     feb      act     300      3000                    

I am trying to do a pivot where the end result of the query is

                    
Company   timeid category  account   amount                                 
C1000       jan     act      volume    100                      
C1000       feb     act      volume    300                      
C1000       jan     act    grossmargin 1000                      
C1000       feb     act    grossmargin 3000                      

In native sql I would write for each account the query as: Select company, timeid, category, 'volume' as account, volume as amount from table where volume <> 0

However, this is inefficient, I want to use variables to pass to the sql query the proper account and pull it's associated data since we have several hundred accts.

Here is the code I developed, but I keep getting can not convert nvarchar to int errors for @p1. Any suggestions would be greatly appreciated.

FYI, I am currenty setting @P1 from a secondary table

                    
USE [Finance]                        
GO                      
/****** Object:  StoredProcedure [dbo].[CustomerPLDataPrep]    Script Date: 10/30/2009   11:45:59 ******/                       
SET ANSI_NULLS ON                       
GO                      
SET QUOTED_IDENTIFIER ON                       
GO                      
-- =============================================                    
-- Author:                                  
-- Create date:                    
-- Description: Procedure to pull data from a temp table, scrub the data and write to a flat file for loading                     
-- =============================================                    
BEGIN                        
-- SET NOCOUNT ON added to prevent extra result sets from                    
-- interfering with SELECT statements.                    
SET NOCOUNT ON                    
                    
DECLARE                       
        @P1 AS varchar(25);                      
        SET @P1 = ' ';                      
        DECLARE                      
                @RECCUR INT                      
                SET @RECCUR = 0;                      
                DECLARE                      
                        @ RECMAX INT                      
                        SET @RECMAX =                      
                        ( SELECT COUNT(*)                      
                        FROM    dbo.tmpACCOUNT                      
                        )                      
                        ;                      
                        DECLARE                      
                                @SQL VARCHAR(4000);                        
               Truncate table [Finance].[dbo].[tmpCustPrepConsol]                                       
                                WHILE @RECCUR  @P1                      
                                        )                      
                                        SUB)                      
INSERT INTO [Finance].[dbo].[tmpCustPrepConsol]                      
           ([COMPANY]                      
           ,[PROFITCTR]                      
           ,[AREARESP]                      
           ,[PRODLINE]                      
           ,[TIME]                      
           ,[SCENARIO]                      
           ,[RPTCURRENCY]                      
           ,[DATASRC]                      
           ,[CUSTOMER]                      
           ,[GEOGRAPHY]                      
           ,[PAYER]                      
           ,[PLANTCUSTOMERS]                      
           ,[REGSALESACCT]                      
           ,[ACCOUNT]                      
           ,[AMOUNT]                       
           ,[SALES])                      
       SELECT 'C'+COMP_CODE               AS COMPANY  ,                      
               SUBSTRING(PROFIT_CTR, 4, 7) AS PROFITCTR,                      
               'NO_AR'                     AS AREARESP ,                      
               CASE                      
                       WHEN LEN(MATERIAL)''                      
                       THEN RTRIM('S'+SALES)                      
                       WHEN SUBSTRING(PROFIT_CTR, 4, 7)='2090050'                      
                       THEN 'S1100'                      
                       ELSE 'S1000'                      
               END AS SALES                      
       FROM    Finance.dbo.tmpCustomers                      
       WHERE   @P1   ''                      
       AND     COMP_CODE  ='1000'                      
       AND                      
               (                      
                       SALES='1000'                      
               OR      SALES='1100'                      
               )                      
                    
                SET @RECCUR = @RECCUR + 1                      
                SET NOCOUNT OFF                      
END                      
end