Thanks Thomas and Jörg, I agree on both, and partially thought at them myself. Indeed a text file relieves from a changed project vi, and can be inspected without launching the program; and a tag allows complete freedom about version format; perhaps though, tagging should be reserved to "meaningful" versions, i.e. one might want to tag only semistable distributables and not systematically every snapshot, which involves a subjective decision.
What I take home from this is - it's not that I haven't yet discovered some advanced option in the project explorer, it's that if I want something specific I have to program it myself with an automated build script.