how to bind a macro to a key?

i wish to bind my assist/follow macro to my W key. can this be accomplished?

War

First, ensure it's on your action bars. Check (via the 2 small up/down buttons if you're using default UI, bongos/bartender if you're not) the action bar number (1-6).
Go to your Key bindings (ESC --> Key Bindings) and find the place on there.

For example, Action Bar 1 Button 1, etc.

Setting keybindings is demonstrated in my video guide:

http://vboxing.net/v/index.php?q=node/87

go to google type in wow bind any key to a macro

first link

/script SetBindingMacro("KEY", "macroname")
followed by
/script SaveBindings(GetCurrentBindingSet()) (or go to keybindings menu and click okay, which works too).

I'm using an addon called Bindpad. It's very useful, mostly because it adds like 20 additional slots for macros, so you'll never be short of space, and you can set them up directly what key you want. Try search on curse.com or wowinterface.com for it. I think I found it on wowinterface.