I've figured out a way how to have macros on the hard buttons that are below the PAGE/MAIN/FAV buttons on a MX-700.

First off within your existing device/activity ie "DVD/MP3", label up a button on the LCD area on a hidden page (say "mac1" on P2/3/4). Now create a macro on that button (ie down + select)
Now select the non-LCD button (ie ch+) then select the "device" drop down box. Select "MP3" device then choose "mac1".
Do the same for other macros/buttons if you need more.

Save and upload. Now when you're in the MP3 page, and press CH+ it'll run the macro (down + select)

This is useful, as chapter rev/skip work fine with CH +/- for DVD's, CD's & Mpeg-IV video files, but for Mp3's you need to press up or down then select to skip. I'm sure there are other uses to add macros on these buttons.

It comes in handy for any single command as well. It's called a "shortcut" in the MXEditor programming manual.

yeah I realize it's a shortcut (any button can access any IR command) like the myriad of other decent learning/PC remotes, but I thought people wouldn't work out that a macro can be sent from the below the page/main/fav buttons as well, due to the limition of the software. Compared to the LCD buttons, where macros can be attached to the button.

If you've done it correctly a little "arrow" and "M" should appear on the pop-up box when the mouse cursor is hovering over the button (ie CH+)

That's actually considered to be one of the bigger advantages the 700/800 has over the 500/600. :)