I'm not aware of any batch method to suppress a password. But since you're using VBScript anyway, this may work:
Set objPassword = CreateObject("ScriptPW.Password")
WScript.StdOut.Write "Please enter your password:"
strPassword = objPassword.GetPassword()
Wscript.Echo
Wscript.Echo "Your password is: " & strPassword
Not all Windows versions ship with a ScriptPW.Password object. If not, there is a way to do this with IE. Let us know. 8-)