Rebinding text skipping to mouse is not that simple, so here's an explanation.

¤ You will want to have rebound previous/next weapon prior to doing this (the default mousewheel binds) if you haven't already, and make sure all your other keybindings are set up properly as well.

¤ Download coalesced.ini editor from http://social.bioware.com/project/1854/#details (this just makes it easier to find the specific bindings and such rather than having to pore through a notepad file).

¤ Open Editor, go to BioInput->SFXGame.SFXGameModeCinematic and change either of the two bindings (or both) to MouseScrollDown or MouseScrollUp (this allows cutscene skipping to be rebound)

¤ Go to BioInput->SFXGame.SFXModeConversation and change the first option (PCConvSkip) to MouseScrollDown or MouseScrollUp

¤ Press F5 with editor open to save the changes.