geocoding data from other fields than "filefield"

hi there,
i very new to geo/geocode and just try to find out how it works.
when adding a "geospacial data" field with the widget "geocoded value from another field"
on the next configuration screen i can only select my filefield "picture" (in the dropdown "geocode handler" only "file field" is available)
shouldn't there be all fields available to e.g. geocode from the node's title?
or do i need to plugin any other "handler" and how can this be done?
thanks
tom