Addon to assign multiple keys to a direction?

[Knytestorme]

Just trying to work out my key bindings to create multiple spreads and I am stuck at a wall.

Playing with things on paper I can map bindings to produce a box and a star ok, but if I try to also add a straight line and half-moon I get into trouble.

Let's look at the 4 spreads I am trying to make, along with the keybindings I would need and see if anyone can suggest me a better matrix for it, or an addon that will allow me to assign more than 2 keys to a movement as the default wow interface restricts us to.

1. Star

 
  1 
3  4 
  2

2. Box

 
3 1 
2 4

3. Line

 
1 2 3 4

4. Half Moon

 
1      3 
  2  4

Keybindings to achieve

 
1 2 3 4 

Shift-O U D L R 
Shift-P R L U D 
Shift-I L L R R 
Shift-K R D L D 
Shift-L - L - R

Now to produce 1 I'd hit Shift-O, to produce 2 I'd hit Shift-O + Shift-P, to produce 3 I'd press Shift-I and to produce 4 I'd hit Shift-K + Shift-L but to create all those bindings would need to assign more than 2 keys to a direction, and that is the dilemna I'm facing.