AIX $SHELL variable and Fourgen Screens

Greetings, Here's one for those using Fourgen CASE tools, and any other Informix'ers who may have some ideas... We've got an application (written in 4gen Screen) that we want invoked immediately when a user signs on, and we don't want that user to have access to the shell (ie, UNIX command line). Our solution was just to assign the program name to the $SHELL variable (ie, make the program the login shell). This works fine when the first screen is called (which is an "application log-in" screen). The user signs on and boom--they're there. However, after the user signs-on here, a second 4gen screen is called using the RUN command. Well...this doesn't work. What happens is the initial screen blanks out for a second, then repaints itself--bringing the user back to where they were initially. From my understanding of RUN, it executes a UNIX-level command as if it were typed on the command line. But since there really isn't a command line to escape to, the program execution bombs out. Is this a valid statement? Are there any workarounds, or other methods of avoiding a shell? We want to avoid giving the user a login shell in general, so setting "SHELL=false" isn't enough (which, according to 4gen doc, keeps one from executing a shell command from a 4gen screen by typing CTRL-O or !). Your ideas, comments, and words-of-wisdom are appreciated! Here's what we got: AIX 3.2.1 on RS6000 SE 5.0 I4GL & ISQL 4.1 Fourgen CASE tools 4.10 Thanks, STEVE ____ ___ ________ ________ /_ _] /_ ]/ ______)/ ______) _/| Steve Morrow, Sr. Programmer/Analyst / _/ / / / (____ / /___ _/ | University of South Florida / _/ / / \\____ ) / _____) _/ | Internet: smorrow@dotrisc.cfr.usf.edu / _/___/ / ______/ / / / _/ | Voice : (813) 974-6889 (_________)(________)(___)______/ |______________________________________