Both Team Build and CruiseControl.NET use MSBuild when they're building the
solution. They just handle source code retrieval, building, logging and a lot
of other things you're going to need if you're trying to automate the build
process.
Team Build comes with the ability to connect to TFS servers out of the box
naturally, while CruiseControl (which is what we use currently until we
upgrade to TFS 2008) just needs an extra free DLL that it uses to connect to
TFS when it starts the build process.
Writing your own MSBuild script isn't the answer you should be looking for.
Research using Team Build or CruiseControl if you're trying to automate your
build process. Depending on which version of TFS you're using, you may need
to download some additional components if you're trying to use a continuous
integration build process. CC.NET comes with this ability out of the box.