You are right, Elements isn't of use for CMYK conversions. Although I believe it is possible to to do a conversion of sorts in Elements a fairly advanced knowledge of color management is required (read, it isn't easy). Here is a quick list of applications that will get you what you need:
Microsoft Publisher 2000
Adobe Photoshop
Adobe InDesign
Adobe Pagemaker
Adobe Illustrator
Corel Draw
Quark Xpress
If this is just a one time deal maybe you can fine someone to allow you access to one of these applications. Otherwise, maybe buy a new, unregistered version of photoshop on ebay.