Hi,
Most workflow software will help you with Office files to CTP, but the low/no budget answer, from my perspective is in two parts: 1) Output PDF files from MS Office programs... if this is proving problematic, print to file PS (postscript) and then drag-n-drop into Acrobat Distiller. (As mentioned above Pitstop is an excellent, if not cheap, addition) 2) Output to CTP: you need imposition software (Preps light maybe?) or set up you own templates in InDesign. Place your exported PDF files into your InDesign files and export that to PDF. Drag that to your CTP hotfolder, or print to your output device. Estabilsh your own best methods, document, review for improvments and standardize.
hopefully that was somewhat helpful.
Mark
PS - MS Office programs are notorious bugs from a prepress persepective. I've heard that "they just output bad code". I'm not sure if that is true or not, but I wouldn't be suprised. Try to work with your customer to keep it simple. Excel graphs and word art can drive you insane. If necessary, open in Illustrator, fix 'em up, and write EPS files, then bring 'em back in.