On 27 Aug 2007, at 04:02, Nicholas Cole wrote:

Textmate is very good at working out which close brace goes with which open brace, but as far as I can see that ability is not available when doing a search and replace. Is that right?

You could work up a macro using the Select → Enclosing Brackets function.

A simple example: Start recording a macro, do a find for “\footnote{”, press → once, press ⇧⌘B to select the enclosing brackets.

At this point you’ll have the brackets and contents of the footnote selected and can do what you want with them.