this.TxtElapsed.Text = String.Format("Elapsed: {0:#0.00}", Utils.FixTimespan(elapsedtime, "MMSS"));
this.TxtTotal.Text = String.Format("Total: {0:#0.00}", Utils.FixTimespan(totaltime, "MMSS"));
this.TxtRemain.Text = String.Format("Remain: {0:#0.00}", Utils.FixTimespan(remainingtime, "MMSS"));
Really don't get me wrong, but this stuff is really rather simply and absolute basic C# stuff. It has nothing to do with any adio processing nor BASS.
I really suggest you first start learning the basic C# stuff, since audio processing is absolutly for advanced and very experianced programmers!