A real simple program I wrote,
it simply copies a block of data from one file
to another location in the same file, or to a different file.

Just double-click the .exe, and it'll prompt
you for a few things:

1) Source file name (DOS format. No spaces)
2) The starting address.
3) The offset of the last byte you want copied.
4) The file to copy to.
   -If it's not the same file as the source, but
    an existant file, you will be asked if you
    want to write to the existing one, or delete
    the existing to create a new file.
    Enter 0 to write to the existing file.
5) The address in the destination file to copy to.