Hi Gita,
I did some investigation. There are options for message output of material documents.
But I would prefer to implement enhancement MB_CF001 in CMOD. Within FM EXIT_SAPLMBMB_001, which is called before a material document change is commited, you have to write your own logic for the checks and the interface. So you are free to define an own file structure or Idoc.
I would probably use the existing Idoc type WMMBID02 and fill the values within the exit.
You can transfer it to the ALE outbound layer by means of FM MASTER_IDOC_DISTRIBUTE. Rest are Idoc settings as usual in WE20, WE21.
Hope this helps to find your solution. It will not be so easy then it is for "out-of-the-box" material master distribution.
/Michael