Concatinate datasets with the same first x letters in a workspace

I have several thousand datasets in my workspace and I want to concatenate (maybe using vertcat?) those with variable names that have the same first x letters together. Any ideas on how to do this?

[Jasmine]

How is the data saved? I'm assuming as a string. You could do something like this for each dataset if count is how many different dataset you have:

cnt = 1
for j=1:count
  for i=1:5
    if i==1
      a = dataset(i)
    else 
      if dataset(i) == a
        if i == 5
          finaldataset(cnt,:) = dataset
        end
      end
    end
  end
end

I think this will simply list all those datasets which the first 5 letters are the same (completely untested literally just written it here). If you need to have, say, all those which start with 5 As in a different variable than all those that start with 5 Bs, you'll need to add this in somehow. At the moment the best method I can think of is a switch-case statement for each letter of the alphabet. But this would be time consuming so maybe someone else can suggest a better method.