Using the same mask for 2 movieclips

Is there a way to use the same movieclip as a mask for 2 other movieclips??

Like this:

shadow1.setMask(shadowMask)
shadow2.setMask(shadowMask)

Ofcourse applying the above directly, will only apply the mask to shadow2. Is there a way to get around this, to have the mask for both movieclips, without duplicating the mask movieclip??

Thanks!