Thank you, Corion. I'll try that later and report back.

Multiple Perl installation are completely normal, and the NET is full of articles and posts showing how to do it. I'm doing it "according to the books", and it looks OK. The problem, IMO, is with the cpanplus configuration.

Why do you want to keep multiple versions of Perl on a machine?
I need to keep the old installation since I have a project which is running fine, and I don't want to disturb it.

Many thanks - Helen