Energy specific Physics process

I want to make a physics list specific to energy range of electron and gamma.
For example, for electron & gamma below 1 MeV, I want to use G4EmDNAPhysics and for electron & gamma above 1 MeV, I want to use G4EmStandardPhysics_option3.

Medium is Water.

How to do that.
Is there any macro command for that.

Thanking you in advance.


see an example $G4INSTALL/examples/extended/medical/dna/dnaphysics