How do I modify class data from an iRule?

I should mention that I DO actually see the modifications I made to the data when I dump it own from within the iRule. It doesn't show up in the actual class, though. I'm assuming the class is copied into a TCL list when I do an lappend, or lreplace. As such it's only modifying this TCL structure, probably as a global variable. What I really want to do is to be able to make modify class data from within the irule, then read that modified class back out from iControl. When I run my iControl code to read the class data, it shows up as the original, unmodified, data. Thanks.