Element materials can use Video or Compositions as texture maps. Load the composition into the Custom Layers/Custom Texture Maps slot in the effects panel. Then when you go into the scene interface, select your material and click on one of the texture maps slots (diffuse, specular, reflection, etc), a window will pop up, click the arrow next to the Load Texture slot, and you will be able to choose which custom layer slot to use.
See Animate Video Textures for more info.
Custom Text and Masks
For more information on this, please refer to the Extruding Text