I think the line would be:
WA_MailObject.ReplyTo = cStr(Request.Form("FORMemail"))
You could add it right above the line:
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.