cFileMask( cFileName )-> <cMask>
------------------------------------------------------------------------------


 PARAMETER:

  <cFileName>       Is a fully qualified filename to search


 RETURNS:

  <cMask> is either the extracted file mask or an empty string if no mask
  was found.


 DESCRIPTION:

  This function extracts the embedded file mask from a directory string


 EXAMPLE:


    +--------------------------------------------------------------+
    |  /* Extract the File mask */                                 |
    |   cFileMask( "c:\windows\*.exe" )    -> "*.exe"              |
    |   cFileMask( "c:\windows\calc.exe")  -> ""                   |
    +--------------------------------------------------------------+


 SOURCE:  

  SOURCE\FUNCTION\FILENAME.PRG