how to set up a variable using concat()

[shadd]

iam trying to set up a variable in a loop using concat like so:

set p=1;
loop2: WHILE p<=4 DO
					   SET concat('Opt_',p)='one';
					   SET p=p+1;
				END WHILE loop2;

but i get an error:

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '('Opt_',p)='one';
                   the variables declared are Opt_1 to Opt_4

Edited August 25 by shadd
clarity