How can I lock device on a particular network frequency using android kernel sources?

**Motivation** My goal is to select or lock LTE frequency bands on mobile devices with Qualcomm chipset. On some devices like Samsung Galaxy S5, we can access hidden menu: *#2263# to select the radio bands, but this secret code is not available for other devices from other vendors, so a more generic way to do this task is needed. Using Qualcomm proprietary tool (QXDM) is another choice but it requires connecting your device to a PC. I want an in-device solution. I am referring diag_qcdm for achieving the goal but this source is out of date and not working. I have a rooted device whose kernel sources are available. Is there anyone who has experience in capturing the communication between the Qualcomm chipset and the ril daemon that are responsible for network selection. I want to lock a device on a particular - RAT - Band - PCI - EARFCN for testing their strength in the field. Please suggest the ways to do it..