/runscript blah.iss
doesn't work? It should given that the /run is processed through isxvg first and it's a reason you can't run after you do a /walk unless you unload isxvg. Not sure I would recommend the hot buttons in VG though, since last I played their contents were stored server side.
You could make your own hotbar inside IS and have it run scripts. Someone had the start of one on the eq2 script samples a while back involving uplink I think. You could use that as a starting point.
