If anyone is using RealLPC (or RealStrat ) in X1, can they help?

I am trying to program a slide down one string via MIDI. Do I:

Send a MIDI Control message via Event list and if so which one?
Automate something in Track automation, although I've looked and can't find anything that works...
Post this question on MusicLab's Forum lol?

Any help would be appreciated. Thanks.

Steveo