Ways to interface another program with MH?

I am wanting to interface another program with mh.  The program has the ability to call other programs and pass command line arguments.  It can also take standard output from the called program as feedback   I could use mhsend but that appears to have no means for feedback.  I am wanting to switch things on an off and get feedback that the command ran properly, or the request might be for some information within mh that I want sent back.

I am looking for some guidance on general ways to approach this.  Would prefer something simple, i.e. avoiding xpl or some such additional layer if practical.  Some perl scripts perhaps?

Jim