Window management — resize another app by app name

Hello there,

Since I’ve been searching all day and initially thought it would be a matter of five minutes, I’m now hoping you can help me.

What I want to do sounds simple: when I load a specific type of Excel spreadsheet, resize that spreadsheet to the left two thirds of the screen, and put another app (in my case Preview) on the remaining third.

I’ve managed to get it done pretty well by creating a custom group with the right rules to only be active for the right Excel files. Then I can resize the current window easily.

However, I didn’t find a way to resize another app where the title is unknown. I managed to select another app with an unknown title, then resize it, the select Excel again. But that’s pretty ugly, and has several other downsides.

I also tried to use a shortcut, as Shortcuts can natively create a 1/3 2/3 split view. However, that shortcut also activates the Preview window. And that means that as soon as I activate Excel again, it triggers BTT again, and I can’t get into Excel.

So, here’s my feature request: would it be possible to add an option in the custom window resize options to select a window by app name (and then take the window in the foreground)? Alternatively, be able to resize the topmost windows in a 1/3 2/3 fashion, choosing which window comes left, which comes right, a bit like in the Shortcuts app, but without activating another window?

Have a great evening / day!