wheel is just a zip.
I think you could unzip the torch-1.6.0a0+b31f58d-cp37-cp37m-win_amd64.whl and copy some binaries as   builder/copy.bat at main · pytorch/builder (github.com) 3.
Then, zip it again.
Note: keep the rezipped package name as  torch-1.6.0a0+b31f58d-cp37-cp37m-win_amd64.whl.