XSLT transformation inquiry

Summary: **This post was created as part of a How to Service Request (SR) **

Content (required): "A Technician is going to request some info (which is a list) from another system thru their middleware, and the middleware is going to update the property in OFS according to the list received from the other system.  User wants me to populate the info in a drop down field where the Technician can choose from that drop down list and send another request to that system with the option selected by technician.

I was thinking on an XSLT transformation with a drop down, but we see in the Modify Property screen a message "If formatting is applied, the properties become read-only" in the formatting section on that screen.  So, does this means I cant use XSLT transformation with dropdown?  Is there any other way to accomplish what user is requesting me?"