I regret, I can't, because I never recomend a program or patch that was not tested by me or a reliable friend of mine.
Try to google for example with "explorer conection limit" ... good luck!
But don't forget that's not on serverside where the limit is - the limit is on client side. ¿do you want that your visitors patch or modify their explorers only to download more files simultaneously. If your upload-speed isn't higher than some 100 kBps your visitors won't have any benefit from having more conections. When a users conection download-speed is higher than your upload bandwidth, more conections will only slow down data-flow.