How proficient can I become on indoor ski slope?

Hi all. To cut a long story short, I am going on a ski trip with a group of friends at the end of the year where I am the only total novice. The others have all skied all their lives, and I will be the odd one out.

With over 6 months to go, I thought I might throw myself into some lessons and practice at the Snow Centre in Hemel Hempstead (in London) which appears to have an actual, indoor snow covered slope.

My question is - if I committed with some regularity to heading out there and practicing, could I become fairly proficient? Enough to be able to keep up with your average skier in Europe? Or, is the real thing so different that the skills will be of limited utility after a certain point?