Which version of Crystal are you using?
If you're on XI (I believe - I know for sure it's in 2008) try the following:
1. Insert an image object in the report using a dummy image from your computer.
2. Right-click and go to the Picture tab.
3. Click on the button next to "Graphic Location" to bring up the formula editor.
4. Add the field that has the hyperlink.
NOTE 1: I'm not entirely sure this will work with a hyperlink - it will definitely work with a network/drive location.
NOTE 2: Crystal will not show .gif files.
-Dell