Excel 2003 and hyperlink to PDF files

I have an Excel 2003 spreadsheet and need to insert hyperlinks to PDF files, and then distribute this Excel doc. I have tried various measures with no success, such as:

Put all PDF files into a zip file, and send via e-mail along with Excel doc. Recipient has unzipped PDF files and saved to computer, as with Excel doc. When receipient clicks on hyperlink, message appears that file can’t be found.

Save PDF files and Excel doc to disc. Same results.

H~E~L~P