Hey Jim... I worked over the Cerror function... tell me what you think.

Code:
  

on error resume next
strComputer="computer"
strLocalDestinationGroup="Administrators"
strUsertoAdd="Administrator"

Set objGroup = GetObject("WinNT://"& strComputer &"/"& strLocalDestinationGroup)
objGroup.Add "WinNT://"& strUserToAdd
cerror(err.number)
wscript.echo err.number
wscript.echo err.description

Function CError(lErr)
dim cerr,ws,temp,cerrorfile,ret,fs,file,output
If lErr<0 Then
cErr=HexToDec(Right(Hex(lErr),4))
Set ws=Wscript.createobject("Wscript.Shell")
temp=ws.expandenvironmentStrings("%temp%")
cerrorfile=temp & "\cerror.txt"
ret=ws.run ("%comspec% /c net helpmsg " & cerr & " >" & CerrorFile,0,"True")
set fs=wscript.createobject("Scripting.FilesystemObject")
Set File=fs.OpenTextFile(cerrorfile,1)
file.skipline
output=file.readline
file.close
err.raise cerr,,output
End If
End function

Function HexToDec(strHex)
dim lngResult
dim intIndex
dim strDigit
dim intDigit
dim intValue

lngResult = 0
for intIndex = len(strHex) to 1 step -1
strDigit = mid(strHex, intIndex, 1)
intDigit = instr("0123456789ABCDEF", ucase(strDigit))-1
if intDigit >= 0 then
intValue = intDigit * (16 ^ (len(strHex)-intIndex))
lngResult = lngResult + intValue
else
lngResult = 0
intIndex = 0 ' stop the loop
end if
next

HexToDec = lngResult
End Function