How to program Lutron Spacer System scenes with MX-500?

I have four Lutron Spacer System (not the regular Spacer) dimmers together in one box that I need to program "scenes" for with my MX-500. I did it once before several years ago with a previous MX-500 that I no longer have, and can't remember how I did it. I can't find anything on the web from either Lutron or URC's sites. Going from memory, I set the dimmers how I wanted them, aimed the remote at them, and learned the remote (repeated four times for each of the scenes) and the dimmers would blink, acknowledging it each time. I seem to recall using channel buttons 1-4 for each scene. I just can't remember the code or particulars on how to program the remote. Can anyone help?