Rename all Workspace Variables and Sub Variables Excluding Certain

Hello, I'm having a bit of an issue. Any help would be much appreciated. I would like to rename all of my workspace variable that are located in my Simulink model to having Lo_21Motor. in front of their current name. If their current name has numbers or unique characters infront, then the Lo_21Motor. would come right after those characters. I would also like to exclude all variables that have (two _ in them) so if a variable is called car__trottl it would not be renamed, but if it is called car_test it would be renamed to Lo_21Motor.car_test . If a variable is called *181(301)+Car_test_391.test it would be renamed to: *181(301)+Lo_21Motor.Car_test_391.test .

Any help would be appreciated!

Thank you