Novel Circuit Idea: Initial Fix Input Voltage & Trigger to Output Variable Voltagage

Attached in here is the block diagram of my circuit.

First i do have a variable power supply.
This is used by my Rload.

My output conditions are:
1. Initial Input Voltage at Rload is 2.2V
2. An external voltage (>3.0V) will then allow a user to variably select the supply voltage to Rload.
3. If this external voltage trigger drops to zero or none, the input voltage is reset to 2.2V.

So if you have novel ideas, please show me what you've got.

Thanks!

This is my idea. if you have one please share:

i plan to use a comparator referenced to 2.2V . if it is greater than 2.2V, my system will resume. The output of the comparator would then output a certain 3.0V into a FET switch, which when ON will directly connect the Variable supply input into the Rload. Any comment, suggestions, revisions?

oopss i have a problem here. need to think more