You will need to 'fake' it.
First, remove the hyperlink and have just a normal text.
Insert a line, double click and format it to dotted. Adjust the line so that
it is placed under the text.
Now, insert an autoshape that covers both the text and dotted line.
Hyperlink to the autoshape.
Format the autoshape to 99% transparency so that it becomes transparent.
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Shawn Toh (tohlz)
Microsoft MVP PowerPoint
(Amazing PowerPoint animations, artworks, games here) http://pptheaven.mvps.org
PowerPoint Heaven - The Power to Animate