Well as Shawn points out, don't think all of these are just conversions. Some might be calls or something.

Here is the general idea, but doubt it would work directly like this.

What are you trying to do?

Code:
$objWinShell = CreateObject("Shell.Application")
$objWindows = $objWinShell.Windows
For $varCount = 0 To $objWindows.Count - 1
  If $objWindows($varCount).Hwnd = $varHwnd
    $objBrowserObject = $objWindows($varCount)
    If @ERROR = 0
      Exit 0
    Else
     $Err = 0
    EndIf
  EndIf
Next