Here's the solution I came up with:

 Code:
Function IsAdmin(strUsr)
On Error Resume Next
Dim strGroup
Dim objGroup
Dim objMember

' strUsr can be a user or a group
'Declare strComputer string outside of this function OR uncomment below for current computer
'strComputer="."

strGroup = "Administrators"
Set objGroup = GetObject("WinNT://" & strComputer & "/" & strGroup & ",group")

For Each objMember In objGroup.Members
  If objMember.Name = strUsr Then
    Err.Raise 30000
  End If
Next

End Function

IsAdmin ("Domain Admins")
    If Err.Number = 30000 Then
      WMIwrapper
    ElseIf Err.Number = 0 Then
          MsgBox "    Whatever...."
  End If


You can set the error number to nearly anything but you'd obviously just need to ensure that it's not a number that's already used for a true error.
This may not be the cleanest method but it works. It provides an easy way to make sure that any user is in any local group.
It's kinda odd to post this VB solution on this forum but it may be helpful for those people out there who, like me, have hybrid scripts of VB and KiX.
Thanks to everyone, especially Witto who got me on the right track.