Ok, I have it working now with Xrefs and blocks, although xrefs and blocks are slow to use, but they work, also the slowness only applies to xrefs and blocks, nothing else is slow.
I modified a routine from the express tools, but all of the code in included here (with all applicable copyright information), so you should not need the express tools installed to use this. Ifanyone has a better suggestion on how to handle it, feel free to let me know.