Informix/Powerbuilder connection question (long)

This is a security question. I'm hoping to start a thread or two about how to setup security from Powerbuilder to Informix. I have a user who will be running a Powerbuilder application on a PC using Windows 3.1. The user will first sign on to the network (Netware) giving his/her user id and password. The application will grab the User ID from the Network (this works!). Then, the application will connect to the Informix database using the Informix.INI file. (This works fine, also.) We (the development staff and I) have problems with this so far. Assuming the Unix password expires (as it will every month,) how will the Powerbuilder application be able to detect the password change and respond accordingly. We kind of think we would run Host Presenter (a vt100 session) to force the user to change his/her password. Then we would have to run setnet, forcing the user to change the password to the new password which changes the informix.ini file. This is a lot of training for the end-users. We would rather run some kind of vt100 session to change the old password into the new password in the background as much as possible. The Powerbuilder application should ask the user for the old and new password. Also, we would rather have the Powerbuilder run the SETNET utility from Informix and fill in the values (BTW, this would ensure that both of the new passwords would be identical) in the Informix.INI file. We know of no way to do this. We are using Powerbuilder 4.0 on 80486 PCs running Windows 3.1 or WfWG 3.11, Informix 6.00.UE1 on an HP 9000 E25 running HP/UX 9.04, and Novix for our TCP/IP connection on our Netware 4.0 server, if this helps. If anyone has solved, found workarounds or has had to live with above problems, please email me directly (or post if you want). I'll summarize anything not posted.