Unfortunately, Al, Windchaser has been out of business for about 6+ months and finding replacement parts are like looking for a needle in a haystack.There may be a substitute for it, but it would mean reprogramming or replacing the receiver in the unit. In my searches, I have not been able to find a universal replacement for AC units. However, there is one place you might try
http://www.remotecontrols.com/ You will definitely need the correct model number of the hand held remote, when search for it.
I hope this helps you and thanks for choosing FixYa.
FYI - You may need to change your cell phone number after posting it on here. As thousands of folks now have it.