How to get older games that use gameport to read USB joystick

[RedRider]

I'm trying to figure out a way that I can use a USB gamepad with games that read the gameport (found on the soundcard in my old computer) on older computers. So far it seems that these older games (for instance Broderbunds Lode Runner) that read the gamepad connected to the gameport can't sense the gamepad if its connected to the USB port. Has anyone else had that problem, and if so how did you solve it? Is there a piece of software somewhere to solve this problem? Thanks for any info you may have.