This set has an example DELMSG.PMM & DELMSG.PRO
Setup to delete all messages that have been on the system for
at least 60 days.

DELMSG.PMM is the "Match" file in WCPro! for Messages.
DELMSG.PRO is the "Command" file in WCPro!

Your batch file for an event might look something like

WCPRO DELMSG

which will use the DELMSG.PRO command file which in turn 
will use the PMM file for the match.