Try using the CPAN shell to do your install.
>perl -MCPAN -e shell
will open it up for you. Something like:
cpan> info /Spreadsheet::WriteExcel/
will get you information on the package(s) available.
cpan> install Module.pm
will install it. When you first run CPAN it will configure your your environment. One quesion it will ask is whether it should ask about dependencies or whether it should simply follow them. As the foreman said when pointing to the line of shovels, "Take your pick."

It will really make your life much simpler if you get into the habit of using the CPAN module. See section 12.17 Perl Cookbook for examples of how to run it or look at the documentation.

Finally, if you're using a different library depository than the standard perl site specific one, make sure to put your directory at the front of the $PERL5LIB environment variable, perhaps in your start up shell. Make sure the variable is set before running the makes or you'll error out. Try looking into Perl Cookbook, section 12.7 for possible suggestions.

MadraghRua
yet another biologist hacking perl....