Not stupid. Just "universal". Go to www.bikeparts.com and search under "brake accessories". You'll find little adjuster barrels that fit into cable stops to provide break adjustment on systems (like running road brake levers) that have no way of trimming the brakes. You can slide it into the cable guide-- should work okay. Problem Solvers (brand name) makes lots of gizmos to solve such problems.

You'll find something.