How to use SQL Expression Fields of Crystal Report 11.5 from VB.NET 2008

I have the following SQL Expression Field in my Crystal Report 11.5

{fn CONCAT({fn CONCAT("SPR_PRODUCT"."PRODUCT_ID","SPR_PRODUCT_SUB_ITEM"."P_SUB_ITEM_ID" )},{fn CONCAT("SPR_PRODUCT_ITEM"."P_ITEM_ID","SPR_PRODUCT_GROUP"."P_GROUP_ID" )} )}  

It works well in the Preview Mode.

But when I use the report in my VB.NET 2008 Project it says the following:

Error in compiling SQL Expression :  
SQL Expressions can not be used in this report..  
Error in File <...>.rpt:  
SQL Expression error: Error in compiling SQL Expression :  
SQL Expressions can not be used in this repor开发者_Go百科t...  

Please help me by telling how can I use the SQL Expression field in VB.NET ?

Thanks in Advance.

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Are you binding a different data source to the report when you run it from your project? If one of the field names is different, you could get an error like this.