+1 char strings as open-bracket/close-bracket

[Kokor Hekkus <originaltruelove@googlemail.com>]

Any way of modifying the syntax table to identify a string of more
than one character as an open-bracket or a close-bracket character.
For instance, you might do:

     (modify-syntax-entry ?^ "($")
     (modify-syntax-entry ?$ ")^")

...to make ^ and $ match each other (from EmacsWiki).  How would I
make the two character strings '#>' and '<#' match in the same way?
The above doesn't work.

Thanks!