As I said before, the ICAO regulation has nothing to do with IFR or VFR, but it depends if you are VMC or IMC.
In all cases...Squawk 7600
In short...VMC: remain in VMC, land at the nearest suitable airport, notify authorities asap.
IMC : Fly last assigned speed and level for 7 minutes
Then fly your filed flightplan routing and level and speed to your destination. Fly the expected STAR and approach, or hold,over the IAF in order to land within 30 minutes of the filed ETA.
It is more complex, in reality, but as you fly turboprops, you really should know this. this is BASIC. did you never practice this during ab initio training?!