Here is a copy of a script I use in our domain. All you need to do is add is as a script for your computers under the computer policy and pass it the parameters as defined in the help section. Don't forget to create the domain local group and an associated domain global group to put in it. Then populated the domain global group with the users. I have another script that can tie a user to a computer, but it requires naming standards, which are often lacking.
'Beginning of Script
' APUTLPUG This program adds any groups that are passed to it as parameters to the local Power Users Group
' APUTLPUG is an acronym for Add Power Users to Local Power Users Group
' Run APUTLPUG.vbs /? for more information
'______________________________________________________________________________________________
'______________________________________________________________________________________________
'Initialize variables
Dim I,J
set shell = CreateObject("Wscript.Shell"

Set net=WScript.CreateObject("WScript.Network"

local = net.ComputerName
CRLF=(Chr(13) & Chr(10))
If Wscript.arguments.count=0 then
Dim Errvar
msg1="This script will not run without a command line argument!" & crlf
msg2=crlf & "Run APUTLPUG.vbs /? for more information." & crlf
msg= msg1 & msg2
Errvar= MsgBox (msg,48, "APUTLPUG Error! No command line argument!"

Wscript.quit
end if
'Get the command line arguments
Argcount=Wscript.arguments.count - 1
For i = 0 To Argcount
ReDim Preserve AdminGroup(i)
If Wscript.arguments.item(i)="/?" then
Help()
else
AdminGroup(i) = Wscript.arguments.Item(i)
End If
Next
Set group = GetObject("WinNT://" & local & "/Power Users"

'Get access to the local security group
For j = 0 To Argcount
On Error Resume Next
group.Add "WinNT://" & AdminGroup(j) 'Add Domain Security Group to the local Security group
Next
'End of main code
'_________________________________________________________________________________________________________________________
'All subroutines are placed after this point!
'_________________________________________________________________________________________________________________________
'This subroutine displays a help message when /? is passed to the script
sub help
msg1="This script was written by Mr. Nice Guy" & crlf
msg2=crlf & "This script will not run without a command line parameter" & crlf
msg3=crlf & "Pass the Domain group that should be added to the local Power Users group as a parameter." & crlf
msg4=crlf & "The syntax is APUTLPUG.vbs Domain/Group." & crlf
msg5=crlf & "Quotes must be added if there are any spaces" & crlf
msg6=crlf & "The following example would add the Domain Local group DL Workstation Power Users from the Test domain to the local Power Users group" &crlf
msg7=crlf & "Example: APUTLPUG.vbs ''Test/DL Workstation Power Users'' " & crlf
msg=msg1 & msg2 & msg3 & msg4 & msg5 & msg6 & msg7
MsgBox msg ,vbInformation, "APUTLPUG Help!"
wscript.quit
end sub
'End of Script