there's always the opacity setting which would make the text semi-transparent...
if you wanted the text to mask out the video, there are a number of ways.
place the text above the video and set the video layer to use the text layer as a track matte using it's alpha.
place the text above the video layer and set the text layer's blending mode to stencil alpha.
add the set matte effect to the footage layer and chose the text layer's alpha as the matte.
add compound arithmetic effect to the text and choose the footage layer as the second source.
place the text under the footage layer and check the 't' option in the modes panel for the footage layer.
and i'm sure there are at least five more ways...
are any of these how you want to make the text and footage work?