PU12, modify File Layout.

Hi,

I need to modify file layout thorugh PU12. Basically I need to add few conditions before the file is generated. The condition specifically are to check a few flags and include/exclude records from appearing in the file.

Please advice how do I proceed with it.

Technical Details:

File layout: ZTE1/ZTE2

User Exit: ZTE1_UEXITS/ZTE2_UEXITS.

But these two exits are NOT to be edited manually! So I am confused on how can I edit them.