keycombination held down while Mbutton is pressed. How??

[invertedsilence]

Hey,
The program I'm working with has CTRL + ALT + Lbutton as a function for moving around the timeline. Holding down these keys allows you to scrub around.
I want to map this combination of keys to Mbutton, since this is similar to how my old software used to do it, however, it's giving me some problems.
I can't get it to register the input properly, and I think I know why.

Code: Select all

~MButton::
    Send, up
    KeyWait MButton
    Send, down
return

I used this script for testing, however, it end up sending both "up" and "down" upon the initial click, even when the button is being held. Because of this, GetKeyState never responds properly.
Is there a workaround for this?
For clarification; I want to hold down the key combo while mbutton is being pressed.