It sounds to me that you have a flaw in your db design. But not sure because I havn't seen your table structure. Are you saying "on" and "fd" are in the same field? You could use "ON" or "FD" in the criteria
It depends, we don't really have enought info. But with the info we have I would guess you should have more than one table. Read up on database normalization.
Let say textboxA contaims fieldA data and textb contains fieldb
if textboxA="Regulatory" then
docmd.openform "FormA"
elseif textboxA="non-Regulatory" then
docmd.openform "formB
End if
Just use the combobox name instead of the text box name. For the security... goto Tools securtiy and you should see some options. Unless you are using Access 2007. For some reason MS disabled User level security in 2007.