If done with Tiff+alpha,
you can add them as a scaffold onto the shot, as well as onto your whole Output/CONstruct.
Therefore you go to CONstruct ==> Output, select your (derived) output and go into Player - if you create a scaffold here, this lies upon the whole output. You can load your TIFF-sequence via the Texturemenu.
Otherwise you can use the Burn-In Plugin for titling (but doesn't work with tiff-files, obviously).