Metronome??? Try this:
Set the tempo to 100 (or whatever)
Set the meter (4/4. 3/4, 6/8, etc.)
Do a 1 measure midi sequence.
Record the hi-hat (Virtual Sound Canvas) on each beat.
Quantize to quarter note.
Save the song as something like 'default'.
Now you've got a 1 measure metronome.
Then, simply copy the measure and paste it with however many repetitions you will need for the song. This, of course, assumes you are doing 4/4. If not, then you'll have to set a different meter before sequencing. This works well for me. It is an extra couple of steps to take before actually starting work on a project but it's a small price to pay for such an excellent program. Whe the project is done, I will delete the metronome tracks to conserve space (but you don't really have to do this as the track takes up little hard drive space. When mixing down, don't forget to mute the metronome track or bring the volume down.
PS: It would be great if Cakewalk would set up a mertonome a-la Cubase, though.