Show a few "input" values and how you want the alphanumeric value to be stored for those values.
You have not done this. . .
I also tried moving PIC S9(16)V9(2) COMP-3 to PIC 9(16)V9(2)
This will work on every IBM mainframe. If it dd not work for you, it is because of invalid data.
then to PIC(X) but it didn't work that way
Comp-3 should not be moved to pic x fields.
To expand on my original request for data - show a few the comp-3 "input" values in hex. Also show how you want these stored after the move.