i am planning to write a perl script to automatically install perl from source on ubuntu 11.04
You can save the effort, apt-src do exactly this for you. In fact perl is installed at the same time that Ubuntu
After the README.gz file you can positively run configure with extra options (i.e: ./Configure -des -Dprefix=$HOME/localperl)
"If you run into any trouble whatsoever or you need to install a
customized version of Perl, you should read the detailed instructions
in the "INSTALL" file that came with this distribution."