Go to QB64.net and download a copy of QB64. It will run most QBasic commands in a 64-bit Windows system. (Although I don't think anyone has a Windows 7 64-bit machine to prove that on just yet.)
Anyway QB64 supports QB and GW-Basic can be converted to QBasic, fairly easily. Once converted, it should run when compiled in QB64.
Another solution is to get a copy of DOSBox, FreeDOS, Bochs, etc., which are DOS emulators. I know they work for 32-bit systems, but check with each and see if they have been updated to function on a 64-bit system.
Another solution is from a previous Laanan Fisher post: "Burn a Linux live cd with DOSEMU+FreeDOS"
You are welcome to post the code here if you would like some help determing how much work it would be to convert to QB/QB64.