I updated the code above, there was an error. Here is another example based on your vbscript. 

? screenreswidth()
? screenresheight()
;? screenreswidth("RemoteComputerName") 
 

 

Function ScreenResWidth(optional $remotecomputer)
  dim $objwmiservice, $colitems, $objitem
  if $remotecomputer=""
    $strComputer = "."
  endif
  $objWMIService = GetObject("winmgmts:\\" + $strComputer + "\root\cimv2")
  if $objwmiservice
    $colItems = $objWMIService.ExecQuery("Select * From Win32_DesktopMonitor where DeviceID = 'DesktopMonitor1'",,0)
    For Each $objItem in $colItems
      $ScreenResWidth = $objItem.ScreenWidth
    Next
  endif
endfunction 
 

Function ScreenResHeight(optional $remotecomputer)
  dim $objwmiservice, $colitems, $objitem
  if $remotecomputer=""
    $strComputer = "."
  endif
  $objWMIService = GetObject("winmgmts:\\" + $strComputer + "\root\cimv2")
  if $objwmiservice
    $colItems = $objWMIService.ExecQuery("Select * From Win32_DesktopMonitor where DeviceID = 'DesktopMonitor1'",,0)
    For Each $objItem in $colItems
      $ScreenResHeight = $objItem.ScreenHeight
    Next
  endif
endfunction