While normally you would use a external compositor, you can use LW for nearly everything except sound.
What are you using to reflect with, is it a background image? then you would need to project an animation onto a poly, just like you would do with a background, using an animation instead of a static image.
For example if you would like to show flames reflecting on your text. you would put a poly facing the text and on the surface you would apply a sequence of an animated flame. The secret is to get it to integrate into the scene, what is in the scene should reflect in your text.
hope that helps some
