need to change user name in po history

at present whenever a po change is happening , the po history is getting updated with ths user name as RFSUSER. Now we do have a requirement that instead of showing the RFCUSER , it should show as the user name . I did research and found it is being read using FM 'ME_CHANGEDOCUMENT_READ2' . Now , is there any exits where we can modify the user name to the desired user name or should we modify the change documents table with the new user name after the change is written.. is it advisable ??

Please advice .