Hi wendyanne, welcome to the forum with your first question. I've made lemoncello with vodka but have no idea where to get pure alcohol for this purpose. When I googled the question, a couple of answers cropped up which might help -
"Buy some Spiritus, Polish "Vodka" at 95% ABV – used to sell it in BWS stores here, dunno about if they do where you live.
and
Every couple of months, I would get either a 50ml or 100ml bottle of ethanol from my local
compound pharmacy.
They range between 95% to 97% depending on what's sitting at the back, which is their large wholesale bottle.
I once got 98% but that was a long time ago."
I daresay you have already seen Uni's
lemoncello recipe here on the forum.
How long have you had your thermomix?