0-10 V input 3 way valve programing

Hi to all,
I have got 3 way valve at my central heating system with 0-10 V input. 3 way valves mix the cold and hot water and gives warm water. I want to automate the warm water temperature. If valve input 0 V it gives only cold water, if valve input 10 V it gives only hot water. For example, if cold water temperature is 20 celcius and the hot is 80 celcius the warm will be 50 if valve is 5 V input. I will use Qubino Z-Wave Plus Dimmer 0-10V output dimmer for control the valve. So what would be my strategy with PLEG? That script is overcoming me so need help.