custom resolution with window sizes

Forgive me if this is covered somewhere or I missed it, but i have a question about how to change resolution inside a window frame in ISboxer, if thats even possible.

I found a window layout i like, that fits perfectly for my 34wide monitor but the resolution is forced into a weird 2294 x 934 size as a result. I was wondering if it was possible to keep this window layout, with this region size, but adjust the resolution within the box to a more manageable 2560 x 1400?

thanks in advance