You won't actually "retrieve" anything in COBOL - when the "move" happens in assembler, the actual receiving field is the field within the cobol program.
When your assembler code begins, one of the first things done is to establish this addressability. If your assembler code "sees" the parm correctly, that is all you should need to do.
so after manupulating the data if i map the address of data to the register 1(R1
You will have already done this and will not need to do it again.