hyperlink question

I am modifying an old vb6 program which creates an Excel spreadsheet. I have added hyperlinks to a column. When I run the program in the IDE and click on the resulting hyperlinks they open in a new window but when I access the spreadsheet via our intranet and click on the hyperlinks they do open, but not in a new window.

The intranet is hosted on a different server than that which the spreadsheet is save on.

Can anyone suggest how I can set this up so that my users can click on the hyperlinks and get a new window?

Thank you.