The most convenient way to extract only some of the tracks in a polywav file

[Xenophilobe]

I've recently been recording podcasts with a RØDECaster Pro, which allows recording polywav files. Due to the limits of the SD card, the resulting files are split at the 4Gb limit. The result is that I have files called POD00001.wav ... POD0000X.wav.

In the end result, there's 14 audio channels in the polywav file, of which I only tend to need channels 3–4. The rest of them take up quite a lot of unnecessarily space. I'm wondering about the easiest and quickest way (perhaps a macro?) to extract only channels 3–4 to separate wav files precisely as they are stored in the polywav. I'd also love it if this would end up in a singular file that stitched together all the 4Gb files, though I can live without that if necessary.