Excel redirects hyperling to php site

Hello!

I'm creating a report in Excel and linking to an external website, where I
need to access a PHP generated page with certain parameters.

The link is (sanitized)
http://someserver.com/path/action.ph...nd_param=value

it shows correctly in the sheet and it is saved as such in the hyperlink
address but when I click on it, Excel instead calls up
http://someserver.com/path/index.php

The original link works, when pasted into the Internet Explorer location
field and the redirection occurs in excel: I checked with a HTTP sniffer and
the original page is never requested.

Any ideas greatly appreciated!

Chris