I would like to search for the pattern "para\_.\{-}variable".
When I am on the highlighted selections (3 pairs of lines in
this case), I would like to yank the highlighted portion to a
register (for evaluation etc).
Well, it's not quite what you describe, but it's like the "n/N"
functionality for finding the *next* (or previous) match and
highlighting it:
:nnoremap <f4> //<cr>v//e<cr>
:nnoremap <f5> ??e<cr>v??<cr>
It might also be handy to have some visual-mode mappings such as
:vmap <f4> <esc><f4>
:vmap <f5> <esc><f5>
So you can continue forward/backward in your searching.
Getting it to highlight the results immediatedly after searching
is a considerably more difficult stunt. Doable, but not without
a number of crazy stunts and mindbendingly opaque mappings. At
least from my determination of matters. YMMV ;)
HTH,
-tim
