Dear Ravi,
I am also having similar issue. I've tried PC00_M40_REMS , but didn't get your point "ELIG" button and also "Retroactive change option" didn't get it. Can you please share a screen shot or any other path for it.
At present we are doing it manually. But good to know SAP provides nice feature for it..Need to explore more 
Cheers,
Nayak