I'm trying to imitate Pete Townsend's synthesizer, which he used in We Won't Get Fooled Again. Although synths were just coming out at that time, he ran a  Lowrey organ into an EMS VCS 3 filter that played back the pulse-coded modulations. Later, he controlled the Lowrey with an ARP 2500, a monophonic synth that "told" the organ to play block chords.
 
I'm pretty sure ol' Pete's not dragging around these ancient instruments on his current road show, but I couldn't find anything on what he is using. Would Sonar's Monark do the trick?

Monark? I t

Monark? It is Native Instrument synth runing through recktor.

I would look at the Arturia V collection to start. You may also want to look at the Overloud VKFX suite.  

Try using rapture. Load one of the organ sounds and have the step sequencer modulate filter cutoff.

Magic Russ
Try using rapture. Load one of the organ sounds and have the step sequencer modulate filter cutoff.

That would have been my suggestion as well. I do all kinds of arpeggiated block chord things with it.

if you really want to use a Cakewalk synth for this, try Z3TA+2.

It's a wavetable synth and don't really emulate any old analogue instruments, but it's great for creating these kinds of sounds anyway.

This isn't included with Sonar, but it's very affordable. Probably much easier to get the sound you're looking for if you're not into synth programming. This is the light edition, but there is also the full XILS 3 and XILS 4 if you're feeling spendy.
 
XILS 3 LE V2.0
https://www.xils-lab.com/pages/XILS%203%20LE%20V2.0.html
 

I agree with Z3ta.  I've done some Who stuff and came incredibly close (imo) using it....  Baba ORielly for instance...

Based on what you wrote you don't need anything fancy.
You can try this.
 
Cakewalk Sound Center (Organ 2) into sonitus wahwah into sonitus modulator.
 
wahwah settings - autowah, tempo 37, freq 4000 & 420, Q 2 for both, mix 100%
modulator settings - tremolo, rate 4.5, phase 0, mix 100%
 
I think that gets you in the neighborhood, but the parameters need to be tuned. As suggested above you can do this in rapture or Z3TA+ or other synths without using sonitus.
 
The more I use sonitus:fx the more impressed I am with them. HTH.