Skydrive & MS Office Web App

So, I've got a customer that's on XP, with a cloud on Skydrive where he has an Excel spreadsheet that's shared so that others can edit simultaneously. He wants to be able to click on an email address in the spreadsheet that should be formatted for auto emailing. However, the stupid web app only allows a user to change the display text. It does NOT allow to format the contents in that column to automatically boot gmail in his browser when you click on an email address; even though, you can format the text to be blue, and LOOK like it's formatted for HTTP. I cleared that formatting so I can start from scratch.

I've checked in the Control Pnl to choose default programs, so that it doesn't automatically boot his local version of Outlook; but it doesn't have the pop-up box to choose your e-mail client automatically when he clicks any of the addresses. PLEASE HELP...PLEASE!

...And if I haven't cleared some old resolved thread JUST KNOW I have tried to contact Ari, or whomever to do the right thing, but you can't get in touch with Ari, and NONE of the directions I ever receive are clear, or work. So, just please HELP.