It is like creating your own continuation of an action command!

I tried another entry moving the cursor down 3 lines at a time without having to take the fingers off the home row. The arrow keys are sooo far out! :-) Of course, all kinds of variations are possible: 1 line, 2 lines, 5 lines down, etc.

I just type as a short form -down;;;;

The entry I created after Emmanuel's model is:
{command}{Down Down Down}{NoSpacing}{PickList}down{/PickList}

In my Commands glossary I chose a short form beginning with the hyphen so it doesn't interfere with the short forms for text expansion, and I like Emmanuel's idea of starting a display form with a sign like the ~