OK, the search link may not be the right onehttps://www.spikeluver.com/Forum/index.php?action=search
but the search button is just up there...
Pari has a point here though, 70% of the time I found the Fic people are looking for by doing a quick search on the forum. For an example my suggestion for 'Long fic from early 2000's' was found here: Adoption Fics: Buffy Slayer/ Spike Vampire
Sometimes though the threads links posted on other threads are not accessible, I then copy the number of the thread and paste it combined with the first part of a working thread address. Maybe through time the forum web address slightly changed?
The forum search engine is very easy to work and very efficient. You can type a part of a word only (I typed adopt for adopted or adoption...) or multiple words in random order.
If you don't find what you're looking for in the thread titles, you can do a search with a classical web search engine inside the website. On Google it's:
Personally, I don't mind helping, I just love a good fic hunt.