I recorded a macro (search for line and paste 3 lines out of the
clipboard "*p )
Without the contents of the macro, this may be a bit difficult to
troubleshoot.
:bufdo @a | update
You likely want
:bufdo norm @a
However, "norm" doesn't allow extra stuff after it (such as your
update). My preferred way to make such batch changes is to
enable the 'hidden' setting, allowing me to review all the
changes before updating them all with ":wall"
From the description of what you want to do, you can also do it
in ex mode:
:set hidden
:bufdo g/regexp/put *
[review changes]
:wall
This will put the clipboard's contents after *every* line
containing regexp. If you only want the first, you can use
:set hidden wrapscan
:bufdo $/regexp/put *
Hope this gives you some stuff to work with.
-tim