Yes, you can - though MMSystem doesn't load the file, seek to the appropriate time and then play for the specified period.
You'll need to perform these fun tasks yourself unless I'm mistaken.
An excellent place to start would be either Charles Pretzold's book, or the following link:
Playing Audio in Windows using waveOut Interface[
^]
You'll need to read-up on the WaveFormateEx structure, and other assorted goodies.
All the best!