Skip,

You can do this with autocorrect. Type the phase e.g., white dog, select
the phrase, press toolsautocorrect options. On the AutoCorrect tab, white
dog will appear in the "with" window. Put [b] in the replace window. Click
add and OK.

--
Greg Maxey/Word MVP
A Peer in Peer to Peer Support

Skip wrote:
I would like to create a document with certain phrases that will
change (but the phrases will come from limited list. i would like to
be able to type in a symbol such as [a] and have a particular phrase
inserted there.
example:
The quick ( ) jumped over the lazy ( ).
[a]=brown fox; [b]=white dog; [c]=black cat; a=dog;b=cow;c=frog

so that "the quick [a] jumped over the lazy b" would print as "the
quick brown fox jumped over the lazy cow".
Thanks