to do this you have to insert an image as your detail link and then apply the "Open Browser Window" behavior (from the behaviors window, not the server behaviors!!) to the image (to apply this to a text link first enter # into the link field of the property inspector, then you can apply the "Open Browser Window" behavior).

when selecting the URL that should be opened, click on the parameter button and define which parameter should be passed on like you would do with the "Go To Detailpage" server behavior. usually it is something unique like the ID. you just have to make sure that the recordset on the detail page filters by this unique parameter as usual...

for more basic understanding of detail pages click here.

here is a hopefully not too confusing screenshot of which panels to use: