How would I randomize several string cell arrays? [on hold]

So I have certain trials:

ST1_lag2 = (['%', '&', ':]', '@', '!', '&', '&', '*', '(', 'A', '%', 'U', '#', '&', '@', '%', '%']);
ST2_lag2 = (['%', '&', '$', '@', '!', '&', '&', '*', '(', '&', 'I', ')', 'E', '&', '@', '%', '%']);
ST3_lag2 = (['*', '&', '$', '@', '!', '&', '&', 'T', '(', 'H', '%', '*', '#', '&', '@', '%', '%']);

Now I want a while loop that can go through all these variables, and randomize them so that the letters amongst the symbols always appear after one symbol in between. Can I do that? If so, Please help me as to how I can accomplish this.

THank You