Simply generate a matrix of indices:
idx = nchoosek(1:33,3);
and then for each row in that matrix perform your calculations, where M is your matrix:
for k = 1:size(idx,1)
ix = idx(k,:);
v1 = M(ix,1); % column 1
v2 = M(ix,2); % column 2
v3 = M(ix,3); % column 3
... do whatever with those vectors
end
