This post is just for me. I want to find this piece of information again whenever I might need it:

The problem: we wanted to avoid creating 20  App-V packages or entries in SCCM just because there’s groups of people having different connection URLs. For now we’d like to have this URL as a property of the AD group we use to assign the App-V application with.

The solution: create a pre-execute script which performs an LDAP query to retrieve the property of the group the user is a member of and set that URL as a user variable. Within the App-V package you can then simply reference that user variable (%APP_URL% for example).

The clarification: It seems to be by design that you can successfully set user variables with a pre-execute script, but you can’t read them within that bubble! Here’s the official answer: KB959452

The solution: we dropped the user variable idea and changed or pre-execute script to generate the application its config files.