Doubt report RPR_ABAP_SOURCE_SCAN

Good morning Gurus.

The functional wants that I change a message text.

But this message occurs within a standard function  probably placed by exit or enhacement ...etc I need know where to change the message.

To search the message I use the RPR_ABAP_SOURCE_SCAN.

In field 'String searched for' i put the current message `In saturday bla bla bla'

in field Program Name I put *

After 4 hours he DON ' T FIND ANYTHING.

1-i SEARCH CORRECTLY FOR THE MESSAGE?

2-EXIST OTHER WAY TO DISCOVER WHERE IS THE MESSAGE?

3-IF THE MESSAGE IS IN TEXT-0* ,CAN i USE THE RPR_ABAP_SOURCE_SCAN TO FIND IT?

I,m working with HR portal the user do the process in Internet portal and comunicate with sap by rfc.

I debuged but I don´t find in standard.

Please help me.

Thanks.