editing binary (hexa) data

[Peter Tury]

Hi,

I have strings(!) like this: "54 68 69 73 20 69 73 20 61 20 73 61 6D
70 6C 65 20 74 65 78 74 2E" and would like to edit them in
Emacs. However the above example is really "means": "This is a sample
text." So I would like to see this "meaning" while I edit it. If I
would have the text ("This is a sample text.") originally, then I
could use hexl-mode (hopefully it can be customized to group by bytes
and not by words). But now I don't know how to use it in my situation?
Or perhaps you know some other mode for me? (hexl-mode's UI would be
ideal if I could disable its original conversion at activation). (I
know I could make a small function to convert my "hexa string" into
"real" string before calling hexl-mode... but I hope you have a better
alternative.)

Thanks,
P