Launch the shuttle unmanned with whatever module can only currently be launched with the shuttle, and have it rendevous with a manned Soyuz or CEV, and then have astronauts fly it to ISS. After it attaches the module to the station the shuttle STAY THERE AT THE STATION.

There are only 2 or 3 modules that currently can only be launched with the shuttle. WHY NOT LEAVE THE ALL THE SHUTTLES AT THE ISS? They could serve as a lifeboats, additional modules, or orbital reseach/repair/rescue spaceships. They could even be used to push the ISS into a more useful orbit. Refueling would become an issue if they were used for in orbit missions but not necessarily a show stopper.