Easiest thing to do in that case, is to have a standard 2 lens varifocal (reading and distance) and have a separate simple fixed focal length specs for computer.
I had to do summut similar. Had a fixed focal to be able to have score in focus when playing piano.
At first, they supplied wrong thing, believing mistakenly they were for using at computer, which it seems is usually what they are asked for. I had to fight tooth and nail to be able to see the optometrist a second time, and when I did, he agreed that what they had supplied me with was useless for the intended purpose.
So I had a pair of piano glasses made, but had to pay a further £80. Yes, I know I should have asserted my rights, and put the matter in the hands of solicitor, but was very unwell at time, and had piano examination looming.
So, I never went back to Vision Express again.
However, current chap that I see is so bloody incompetent, I think I maybe will have to, as my vision is seriously deteriorating.