How to solve this unicode to ascii convert vb6

Hello everybody. I have Unicode to ascii covert nv6. My  problem  is  the  following:
I  have  to  write  a  xml  file  formatted  according a  specific  xsd  and  dtd. I've  created  my  xml  file writing  it  with  VB6 ( put #fn ,,bytearray of my file ). In  particular  the  byte  array  contains only significant  bytes  without  0byte. But  if  I  open  it  by  ULTRAEDIT  I  see  the  file  written  with 2bytes/char  ( starting  with  FF  FE  bytes ),  and  appears ( seeing it in hex editor ) like ÿþ<?.x.m.l.  and so  on  where "." correspond  to  a   0byte  in  hex part. The   difficulty   is  that  the  application ( 3rd part ) that  must  CHECK  this XML  discards  it  because  of  that  code.