David-

>How can I get the "Gen" to go back to a totally empty "gen"?

It's not intuitive, IMO, but if you search on General Fields | Clearing you should find it in the help.

IAC, you simply issue APPEND GENERAL cFieldName without any additional parameters. The following demonstrates it:

create cursor temp (g1 g)
append blank
append general g1 from getfile('bmp') && you should see the general field with "Gen"
append general g1 $$ Now it's "gen"