GridView - HyperLinkField: bind to a mailto instead

[Support]

Hello:
I have a stored procedure that returns either a http or a mailto depending
as href's
I would like to have displayed a description text with underlying either:

<a href="www.">some text</a>
or
<a href="mailto:[email protected]">some text</a>
Any thoughts on how to do that ?
Perhaps the hyperlink field is not the way to go on this...
Thanks
Terry