Limit number of characters returned

[Mark]

Is there way to limit the number of characters returned from a stored field?
For example:

Say I have a document (~2K words) and I search for a word that's 
somewhere in the middle. I would like the document to match the search 
query but the stored field should only return the first 200 characters 
of the document. Is there anyway to accomplish this that doesn't involve 
two fields?

Thanks