Well on windows you could automate Word using Win32::OLE to cause Word to output the document as HTML, or indeed if you wanted to get fancier then you could read the elements of the document yourself and then construct the HTML yourself.

On a Linux machine I would suggest using the program mswordview that can be found at http://wvware.sourceforge.net/ - of course this is not Perl but you can use it from your Perl program

/J\