As far as the current control is concerned, this configuration allows you to adjust the current limit within certain range. For example, if R2=20Ω (rated for at least 20W) then the minimum current will be ≈35mA. To have the current limit adjustable, you will have to connect in parallel to this 20Ω resistor a 100Ω variable resistor in series with 1.3kΩ resistor. The VR will come at the T1 side, and the base of T2 will be fed from the middle pin of the 100Ω VR.
If you would like to control the output voltage by a microcontroller you will need to use an isolated opamp or an optically isolated linear optocoupler.
This can be done by replacing R3 (voltage control) with a transistor-based differential amplifier driven by that isolated circuit, and will require extensive modifications to the previously suggested circuit ..
Regards,
IanP