I'd look at manipulating the data once it's in a worksheet, if possible. If
it is not possible then you may have to use VB's low level file i/o
functions. If you haven't worked with them it can be a challenging
experience but you can get the byte-by-byte control that you want.

This is a pretty good article on the subject:

http://support.microsoft.com/default...eio/fileio.asp

You might look at using Line Input and parsing/concatenating according to
your needs.

--
Jim Rech
Excel MVP