Yes it’s now possible to use more than one file in a CL program. You need to give your files an OPNID on the DCLF statement in your CL program and use the OPNID parameter on your SNDRCVF statement.
“Now possible” — this means that you are using a recent version of the operating system. Multiple DCLF/RCVF support became available in V5R3.
If you are using an earlier release, set a CL program to declare and display the DSPF. When the display values aree retrieved, CALL a second CL program and pass the needed values to it. Declare the second file in the second program.