This is a tough one to answer, because it throws people off when there are both incremental arc and radius arc styles of programming in the same G code file for arc centers.
To cut to the chase, the FANUCARC command can be issued on-the-fly to swap between incremental and radius style arcs through either a MCODE that issues
FANUCARC=0 for absolute arcs
FANUCARC=1 for incremental arcs
FANUCARC=2 for R for radius.
Plus you also have to use an IF THEN to change teh CW & CCW command line from
If you were clever you could use the ISTHERE command in the GCODE.FIL file inside G2 and G3 to test if there is an R on the G2/G3 line or not then based on the result issue IF THEN FANUCARC 0,1 or 2.
This would trap for the programming style automatically on-the-fly