SeekMusic(id, pos)
id. The music object does not have to be playing. If the
music is playing and you call SeekMusic(), it will immediately skip
to the specified position. The position is specified in milliseconds.
Thus, if you want to skip to the position 3:24, you would have to
pass the value 204000 because 3 * 60 * 1000 + 24 * 1000 = 204000.
Please note that this function does not work with Protracker modules.