Cool Down help

[argut5001]

sorry in advanced if i spell bad heh.

I'm Trying to Make a macro that will

1 Target Nearest Enemy

2 Charge

3 Hamstring

now the problem is i get it to target then charge. But it always tries to cast Hamstring before the cool down is done. Is thier a way i can get it to wait a certain amount of seconds or to acumulate a certain amount of rage before it uses Hamstring?
Sorry im new to the game and when i found out about the Macro Commands i wanted to try and make one myself.