Sure. The button names changed in build 104. I'll use the new names from 104 in these examples.

To start off, here's a hotkey that does what you described. Your two WoW's are the same size, at the same location. You press the left button and both windows get clicked.

Code:
<Hotkey LButton>
<SendWinM wow1>
<MouseClick NoMove LButton>
<SendWinM wow2>
<MouseClick NoMove LButton>
Like I said earlier, you don't need to have the windows in the same place. They don't even have to be the same size. If you move them or resize them, take "NoMove" out of the second <MouseClick> like this:

Code:
<Hotkey LButton>
<SendWinM wow1>
<MouseClick NoMove LButton>
<SendWinM wow2>
<MouseClick LButton>
Those hotkeys work okay but they might be annoying because they *always* click both windows when you press the mouse button. It might be better to make a hotkey that does that only sometimes. Here's one way to do that. Pick a key on your keyboard that's easy to find, but doesn't get used much. On US-English keyboards, the Grave key (upper left corner) is a good choice. Declare that as a custom modifier (a shift key). Then define the hotkey so it gets triggered only when Grave is held down simultaneously with the left button. The result looks like this:

Code:
<UseKeyAsModifier Grave>
<Hotkey LButton>
<SendWinM wow1>
<MouseClick LButton>
<SendWinM wow2>
<MouseClick LButton>
And that leads up to Katharsis's example from this other thread:

HotkeyNet + AOE!