Postscript is a page description scripting language. In one sense it's just text. If you have a PS version of the original Word template and the PS includes place holder text for the merge fields then the job "simply" becomes: use Perl to replace the merge fields in the template PS file with the merge field entries from the input data.

I've never used PostScript::Simple nor looked at it. However Perl is pretty good at manipulating text files and both the PS and input data files are text so maybe you don't need the module, or maybe the module makes life easier. Kinda sounds like your job to find out :-D.

Seems to me the exercise isn't about Perl, but is more a test of your programming skills which ought to transcend the specific tools you are asked to use.