I know I can transpose an entire track, but how do I do this halfway thru the song? I was hoping to insert a MIDI command in the track view.

I've scoured this board, and the 'net for the midi command for Key up or down.. can't find it.

thanks

You don't mention which Cakewalk program you're running, but in older versions (maybe new ones, too) click Insert>Meter/Key Change.

Home Studio 6.  Old.

Thanks.   I can also select and Process...  Doesn't look like insert tempo/key works.  

I've got SHS 6. too. It may be old, but it's the best.
 
I may have misunderstood. You want to transpose, not change keys.
If the Transpose VST is automatable, you may be able to insert it in the track FX bin, click the W (Write) button and turn it on at the proper moment.
I've never tried that.
I have split the track, dragged the part I want to transpose to a new track and inserted the Transpose effect in the new track.

2oldman

I know I can transpose an entire track, but how do I do this halfway thru the song?

If you already know how to do this for the whole track, then you can do it for part of the track by selecting only the range that you need to transpose before applying the process.  Splitting the midi clip (by clicking on the clip at the desired point and hitting the 'S' key) first makes it simpler.

Key up or down will transpose the entire track non-destructively. 

To transpose part of a track, select the measures you want to transpose and Process-Transpose.