Can't be done, as per
http://www.eqgui.com/showthread.php?s=&threadid=2267
However, have you heard about the /autoinventory command now in game? Make a hotkey with your forage ability number in the first line, a brief pause on the second line, then the /autoinventory command on the third line. ie:
/doability 5 (or whatever you have your forage set to)
/pause 2
/autoinventory