In MySQL, you can put BACK TICKS (the ` character, usually on the same keyboard key as the ~ tilde character) around any string to make it a valid column name.
So, for example, you would write:
SELECT * FROM sometable WHERE `$aSomeGuyName$fAdress` LIKE 'John%'
Note carefully the difference between back ticks and apostrophes. It's hard to see, so make sure you use the right characters.