Well, it's been over 4 years since I used ClearCase, but I vaguely remember having a similar problem. Unfortunately for you, I did have root on the build box, so the solution for me was to make /usr/local/perl5 (and other necessary places) into vob-exported directories (Is that the right term? It used a view to figure out what was there, but you didn't need to be in the view to see it).

If you can't get root permission, perhaps your sysadms will give you a suid script that installs the (newly built) Perl in /usr/local/perl5/..., which you could then run after building perl but before building extentions.

HTH,
--roundboy