Here is H2L document attached for the cobol program that you can call using Power Exchnage.
Its for ZOS, But i believe we can try for AS400 as well. You can also get the details from Navigator guide
"Calling a User Exit Program by Using the PowerExchange CallProg Function"
Check out DTLREXE in the PWX Utilities manual.
Create a file called rexecmd.txt:
uid=ABRISTOW pwd=XXXXXX loc=AS400NODE prog=system parms="CALL PGM(DTLCRYPX) PARM(PSWD)"
Then call DTLREXE from the command line:
P2X-00116 KEY Warning - license(1) has 25 day(s) before expiration.
P2X-00750 DTLREXE Input LOC=AS400NODE, PROG=SYSTEM, PARMS=CALL PGM(DTLCRYPX) PARM(PSWD), UID=<ABRISTOW>.
P2X-00755 DTLREXE Command OK!