Tim gave you the solution (:foldd). But I think there is
one small problem with operating on non-folded lines;
not with Tim's solution but with folding in general.
Namely, you cannot fold single line.
I remembered this after I got back Meino's reply detailing what
he wanted to do.
Fortunately, the :g command can take a more complex if|else|endif
ex command as its action, so if the protected lines can be
determined by a regexp, one could do something like
:g/gold/if getline('.') !~ 'exclusion regexp' | d | endif
where "d" is the delete action you want, and the "exclusion
regexp" is a regexp that finds those lines on which you don't
want to match "gold".
There's also a script/plugin (by Dr. Chip?) called something like
"logipat" that allows for combining patterns with logical
connectors that might also be helpful in such a scenario.
Just a bit more fodder for thought...
-tim
