mcedit macros can't do F7

[chris glur <crglur gmail com>]

Perhaps others can give ideas for some more mcedit optimisations.
Firstly, here's one that I often use, to clean up USEnet lines
> > which have
> become
badly formatted, due to unintended line-breaks.
--->  "Format paragraph     M-p"
takes the marked block and does: [I'm writing this from a bad memory]
remove all ">" = sed ...
| replace all EOL with <space> = tr ...
| fold the lines at word-breaks [default len < 80] = `fold`
then I've got something to reinsert the ">" ... ">>>" as
     per the original FIRST line;
---
How would you [without going via : Format paragraph  M-p]:
  delete the next [on this line]: "[" string "]".
??
--
Manually, you'd use the <F7> key: twice.
And the key-macro of your manual-steps, is no good because it
stops for the <F7>'s input/s.
--
Perhaps:
 Ctl-o = to get access to shell
 q = call a script that shows a menu
 [ = select the filter which deletes : "[" string "]"
will do it ? But no, since <Format paragraph   M-p>
needs the line to be 'marked'; which is already 2 key-strokes.
--
We want ONE key-stroke to do oft-repeated tasks: like mc has
already got, except we want to add/extend our OWN needs.
The key-macro facility is good, except that it stops for F7's argument.

== TIA.