That sounds cool having auto build tool for daily release/build/test. It's fine to be a bat file or something else. I create one bat for my project this noon, and it real works very nice.
1. Get the latest source code copy from CVS(or some other source control tool)
2. Run the sql script file to rebuild the database. (optional)
3. Run unit test via NUnit or some other tool
4. Build the sln file.
5. Run UI based(web/windows app) or Unit(console app) auto-test scripts
6. Generate simple report
Great!