I haven't tried this, but in Windows Excel,
pressing the F2 key does what you're wanting.
In the fitaly web site, (http://fitaly.com/winmobile/fitalymacros.htm),
it says "Function keys F1 to F12 can be produced with the Fitaly macro language via the Specials -> function key menu."
Maybe try setting up a macro to press the F2 key?