here is something i tried, for some reason it is not working perfectly for the X value (its just a decimal off, and i cant figure out why!), but it does work for the Y value. It should send you in the right direction anyway! Oh and yes, the patch is a bit of a mess inside :-(
I figured it should be doable with [coll] and converting the floats into symbols for storing and retrieving. Seems to work fine. There's the float precision issue (try typing 55.567 into a message box and you'll see what I mean), but as long as the numbers are consistent, you can retrieve the data.