Not exactly the way you are looking for,
but it does exactly what you want:
The bvi is a display-oriented editor for binary files (hex editor), based on the vi texteditor. If you are familiar with vi, just start the editor and begin to edit! A bmore program is also included in the package.
> > Regards > Dominique > > -- i use this in my status line. dec/hex\ \%03.3b/\%02.2B\ shows decimal and hex values for char under cursor ala with cursoron an equals sign char dec/hex 061/3D