Go to tuner configuration, select adavanced, select LNB, select diseqc1.2, where it says 'use usals for this sat' change to no

then will appear an extra setting where you can input your vbox positioner number. If you already know the number stored in your vbox for each sat then just enter the number and press ok to store.

If you want to find the sats and store position number then you will have to download the positioner plugin, I thinks there is also a satfinder plugin.

I always use logical position numbers in my vbox for eg, astra19.2 = pos number 19, 13e = 13, 28.2e = pos number 28 etc etc. Makes things alot easier.