You could manually download the file and put it in the CGI directory like you said, but the preferred way would be to download the gzipped tarball, extract the contents and run

perl Makefile.PL LIB=/your/perl/lib PREFIX=/your/perl/lib
make
make test
make install
[download]

Replace the path after LIB= and PREFIX= with where you want it installed (probably in some directory in your home). In the script wher e you plan to use the module, make sure to do a use lib '/your/perl/lib'; to add the path to @INC.

Also, if you asked, the sysadmin would probably install it site-wide as it is a common and very useful module.

Update Added the PREFIX and use lib ... bits which I forgot before.