VB Code:
  1. Declare Function ReadFile Lib "kernel32" Alias "ReadFile" (ByVal hFile As Long, lpBuffer As Any, ByVal nNumberOfBytesToRead As Long, _
  2.                                                            lpNumberOfBytesRead As Long, lpOverlapped As OVERLAPPED) As Long
may be of some help. http://www.allapi.net/apilist/ReadFile.shtml