I don't have that pattern for you but here is a link for the interlocking rings which might help. This is a pretty good link it shows the steps on how to do this - I would think you could just add more rings and then a fill in stitch on the outside to get your square. HTH ;o)

Here is a link that might be useful: Waldo's puzzle square

Uh, instead of fill in stitch, you should make a granny square out of it, it looks like three double crochets chain three then three more double crochet stitches in the corner, chain one in between the rest of the three dc's then a row of single crochets as the last round.