dim strUser  : strUser = CreateObject("Wscript.Network").UserName
dim blnFound : blnFound = false

for each objUser in GetObject("WinNT://./Administrators").Members
    if objUser.Name = strUser then
        Echo strUser & " is a member of local administrators."
        blnFound = true
    end If
next

if blnFound = false then
  Echo strUser & " is not a member of local administrators"
end if