After <FN>+<RCtrl> you always press at first the key, which you want to reprogram. In your case <7>.
!! For some strange reason you have to press this first key often 2 or even 3 times - until the right LED under the spacebar reacts. !! (I think it changes from static to flashing (I have my vortex boards not here at the moment to check.))
After the change of the right LED you simply enter, what the 7 key shall do. This can be either one key press or a whole sentence. In your example press and hold Shift and enter KTMSA like you would in an editor. When you're finished, press <PN> and - if you don't have any further keys to reprogram <FN>+<RCtrl> to exit program mode.