Thanks, but I am looking to one on this site - esp in the excel questions forum? I can't seem to locate a search bar.
Do you not have a blue bar towards the top of the screen with:
User CP, FAQ, Community, ..., Search
If you are looking to search specifically in the Excel Questions forum then follow the steps in my last post. Once you get into the Advanced Search page you can select the forum(s) you want to search in towards the bottom right of that page.
Alternatively, if you are already in the Excel Questions forum, look in the second blue bar (just above the first orange one). At the very right is a 'Search this Forum' link. Again, if you choose 'Advanced' from that drop-down, you will be taken to the same advanced search page as the one I described above, but the Excel Questions forum will already be selected for you.
In either case, you can now also search for a particular User Name (any post or threads started by that user) and for particular Keyword(s) (anywhere in the post or in the Title only). Note though that the keywords search ignores words less than 4 characters long.