Unfortunately No.

"IF RCIF = 1 THEN GOSUB coms" will not work with the Software-based SERIN/SERIN2 commands.
The RCIF EUSART Receive Interrupt Flag bit in the PIR1 PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 1, is tied directly to the HW EUSART RX pin (PORTC.7). It is part of the PIC functionality of the EUSART hardware module.