Yes, it is possible.
First, you will need to change the swapping drop-down in your Window Layout to not start with "always" in order to achieve this. This drop-down box is what makes the window automatically swap when you switch. If you set it to "only when I press the Swap Hotkey" for example, this gives you a Hotkey (configured directly below the drop-down) that you would press within a specific Window in order to bring it into the Active Region (where one of your windows will go at launch).
The only piece you will be missing is a method (Hotkey) to push the window from the Active Region into its Home Region.
Here's how to make it
1. In the top left pane under Key Maps, select a Key Map to put your new Hotkey in
. If your Hotkey will not be something that interferes with your ability to type (e.g. if you make it Pause or something, you don't normally need that key for other purposes), you could put it in the "Always On" Key Map (called "Control" for WoW players), otherwise you could put it in either the Combat or Non-combat and it will be toggled by the standard Key Maps toggle.
2. In the bottom left pane, right click Mapped Keys and select New Mapped Key
3. Give your new Mapped Key a name
so that it's not "New Mapped Key", e.g. "Push window back". To rename it you can right click and select Rename, or press F2.
4. In the bottom right pane, at the top, set the Hotkey
by clicking the <. This is the key you will press to push the window back.
5. In the bottom left pane, expand your Mapped Key
("Push window back" in my example) so that under it you should see Steps, 1
6. Select Step 1
(the 1 under Steps)
7. In the bottom right pane, right click Actions and
, under Window Actions, select New Window State Action
8. Now, to the right of that, you will have a couple of options...
8a. Set the Target drop-down to "Window:All w/ Current" - this will tell it to send every window to the Home region, so you can use this hotkey from any window not just the one that's in the Active Region
8b. Set the "Where" to "Background" (another way of saying its Home Region); this is default
8c. Set the "How" to "Instantly (emulate)"; this is default. This option affects window swapping speed and whether the display may be scaled
(which is fast to switch) instead of adjusting the resolution (which is slow to switch).
9. Export to Inner Space to activate your changes
That should do it.