When you say "behind an object" is the object part of some video?
If that's the case, first step is to duplicate the video layer. Next you would mask out/isolate the object you want the text to go behind. If the object doesn't move a simple mask will generally do the trick, but if you want the text to go behind something that is moving, then you will probably need to do a frame-by-frame rotoscope. The last step would be to animate some text in between your top layer with the isolated object and your bottom layer with the rest of the video.
Johnny Cuevas, Editor
"I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work."
---THOMAS EDISON on inventing the light bulb.
If I remember correctly, a couple of the CC effects, Cylinder, and Sphere, maybe, have the option to create a "front" and "back" version of your shaped text, then you use a copy above and beneath your "wrapped" layers. Of course you still have to create the alpha that John mentioned above.