FAQ.How can I get the short name from a filename?
Feedback.

Answer: Try this function:
Example:

Function fGetShortPathName(sLongPathName As String) As String
  dim lpShort,lpLong As MemoryBlock
  dim iBuff,iLen As Integer
  
  #IF TargetWin32 then
    Declare Function GetShortPathName Lib "kernel32" Alias "GetShortPathNameA" (lpszLongPath As Ptr, lpszShortPath As Ptr, cchBuffer As Integer) As Integer
    
    lpShort = newmemoryBlock(255)
    lpLong = newMemoryBlock(len(sLongPathName)+2)
    iBuff = 254
    if right(sLongPathName,1) <> "\" then
      lpLong.CString(0) = sLongPathName+"\"
    else
      lpLong.CString(0) = sLongPathName
    end if
    iLen = GetShortPathName(lpLong,lpShort,iBuff)
    
    if iLen > 0 then
      Return lpShort.CString(0)
    else
      return "### Error Getting GetShortPathName: " + sLongPathName
    end if
    
  #endif
End Function

Notes: The MBS plugin has several functions for this in the folderitem class which work even on Windows NT where this declares fail.