Plasmarb,
I think you still don't quite get it.
If I were you, I would forget about 'QNE'.
If you're planning to fly a microlight around the UK, you will definitely need to understand QFE and QNH, and you seem to have some idea about those two.
Here is a brief outline of altimeter setting procedures that you may find useful:
Pre-flight check
Set the aerodrome QNH. The altimeter should read within 50ft of the published elevation.
If you like, you can set the QFE and the altimeter should read within 50ft of zero.
(If you want a more detailed check of the inner workings, for an altimeter that is new to you, or has recently come out of maintenance, you can verify that adding 10hPa to the setting shows a 270ft climb and vice-versa, and that there is no unconnected movement of the needles or sub-scale, especially if you pull or push gently on the setting knob while you turn it.)
Departure
Set the aerodrome QNH.*
*If you are staying in the circuit, some aerodromes might prefer you to set QFE.
Cruising flight
Below the Transition Altitude (generally 3000ft in the U.K.), use either the QNH of a nearby aerodrome or the Regional Pressure Setting (RPS).
If you plan to cruise above 3000ft in class G airspace, you will be above the transition altitude and you will set 'Standard' or 'ten-thirteen'.
You will then fly at a Flight Level that is suitable for your magnetic track (semi-circular level).
MATZ penetration
The controller will give you a clearance based on the aerodrome QFE. He/she will pass the RPS once you exit the MATZ.
Approach and landing
You can use the destination aerodrome's QNH or QFE, as you prefer.
Bigger airfields tend to just pass you the QNH but QFE is available on request.
Small airfields might just pass you the QFE. Again, QNH should be available on request.
Nobody will mention 'QNE' as it is not an altimeter setting. It is the reading of the altimeter set to 1013.2hPa when the aircraft is on an aerodrome. Put simply, it (QNE) is not relevant unless the QNH is abnormally low, in which case it is probably blowing a gale and your microlight should be in a hangar.
If you want to derive QNH from QFE, a quick way is to divide the airfield elevation by 30 and add that to the QFE.
Similarly, you can derive a QFE by subtracting 1hPa from the QNH for every 30ft of airfield elevation.
Most airfields in the U.K. have an elevation of 600ft or lower, so the conversion between QFE and QNH should be fairly easy.
Having said that, I think you can see that there is a big potential threat here for making a cock-up and setting the wrong number on the sub-scale, especially in a noisy, draughty environment. That is why IFR procedures need to be much more prescriptive.