You should use the CodepageFile object in the BytesConverter library.
You appear as an unlicensed user so I don't remember if this library is in the demo program.
Additional libraries are only accessible for users who baught B4PPC.
If you can't access my BytesConverter library you can do it a longer way round with the BinaryFile library which I think is available in the trial edition.
You open the BinaryFile with New2 passing it a files opened as Random. Dim a byte array with Length and read the bytes into it with ReadBytes. BytesToString then gets you a Unicode string to use in B4P that is converted from the format that you specified when you opened. The int value to pass for ISO-8859-1 is 28591.