You should very much try to work backward and try to get these dynamically named variables into MATLAB in a different way. For example, if you are somehow reading them in from a database via a for loop, maybe write directly into a matrix from there. Or something better than dynamically named variables!
But, if you are really, truly stuck with these variable names ... yes, you can work with them.
I will probably forfeit all of my Answers street cred for even mentioning eval, but ...
HH_all = zeros(100,108);
for nh = 1:108
eval(sprintf('HH_all(:,%d) = HH_%d',nh,nh))
will write each of your variables into a column of the new variable HH_all.