What I have here is an Open HH in one instance of DropZone, and a Closed HH in another instance of Dropzone. That would be your two separate synths.
 

 
I then insert Sonitus Gate on the Closed HH, and Send the Open HH to the Sonitus plugin on the Closed HH track. Set the Gate to Duck, bring down the Depth, and set the Hold and Release to your liking. The Closed Hat will now choke the Open Hat.
 
 
 

Ahhh drop zone, wish you'd said this in your first post
 
I'm assuming (perhaps wrongly) that you've checked the hi-hats in SD3, addictive drums and any other drum vst's you might have but none of the hats give you the sound you're after?
 
If you haven't and you want realistic (acoustic) sounding hats then what I think you're trying to achieve (a regular open/closing hat) could be achieved much easier and probably sound much better in virtually any other drum vst than in drop zone.
 
 
Steve

I think you're confusing me with the OP. DropZone was simply an example for the OP regarding choking two sounds from two completely separate synths. It could've been a Hat sound in SD3 choking a Hat in AD2, but I used DropZone as an example because it was the quickest and easiest way to show the routing and gate settings.

I was yeah sorry, I just looked at your avatar and thought it was the ops.
 
Still think using two synths is a very unorthodox and round about way of getting an open/closing hi-hat sound but I'm thinking he/she must be wanting something else.
 
Steve

Hello,

I am the OP.  I am making electronic music and my hats are not even truly hats.  They are synthetic percussive-y type sounds that I want to choke from different softysynths.  FidelityMusic's and others suggestion about the Gate is great.

Thank you!