Using CC2592 Front End with CC2541 in proprietary mode?

Hi,

In section-8 of Application note SWRA422, 3 steps mentioned to have automatic control of CC2592:
1- The specific pins on CC2541 be connected to control pins of cc2592: This is match with our design
2- the registers listed in Table 8.2 need to be changed from the recommended CC2541 settings to control the CC2590and give optimum performance: I did that.
3- use of HCI_EXT_ExtendRFRangeCmd. This command is used to configure the CC254x to automatically control the CC2590: I am using the only available code for cc2541 proprietary and it does not have HCI_EXT_ExtendRFRangeCmd function. Where this function should be found and if it is for BLE how it should be integrated to proprietary mode?

Thank you,
Amir