How to show row number in case Flat File validation exception

We are using Biztalk 2006R2.

When flat file validation is failed In Biztalk,  error message will be shown in event log, saying which element has error. However, it does not contain the line number information.

Therefore, it is very hard to configure out which lines contain the error, especially when the number of lines is large, say over 10000 lines.

Is there any way to show the line numbers in the error message?

Thanks.