Potion for changing global variables

The inspiration for this was the very long and drawn out Jaheira romance. I figured if i could make an item that could change the local lovetalk variable and the global romance variables, it would make it more feasible, as I tend to fly through the game. I found the Set Global Variable effect in Near Infinity, but I can't figure out how to choose the variable to change. Any pointers?
Btw, I call it Love Potion No. 9.