How to capture error_message when i use "Error Handling"/"Use Overflow file" option in target table

Hi,

I am using "Error Handling"/"Use Overflow file" option in target table to capture errors like "Unique Constraint".

So, When a duplicate key arrives it will be thrown to overflow file and the job is getting succesfully executed aswell as error will be shown in error file.

But if i use this option, catch block will never be executed even if there are errros.

Here i want to capture Error_Messgae() into a gloabl variable (like .. $ERROR=ERROR_MESSAGE()) where this can be done in catch block only!!!

Can some one help how to capture error message when we use this option in target table?

Thanks ,

Amar.