A very simple script I wrote for myself to lock my Huawei E3372 to Band 28. This is often the only useful band in rural parts of Australia, but for some reason the Huawei is often reluctant to use it.
This is entirely unpolished and I know almost nothing about 4g or usb modems, so no guarantees, but it's here in case anyone finds it useful as a starting point.
If you want to adapt the script to lock different bands, checkout the reference PDF. The relevant params are in section 15.2, p335