coloring keywords in conversation

[stef]

I'm using Emacs 22.2.1 to edit a text file containing conversation,
such as:
    Robert said, "Hello there."
I want certain keywords to be colored. For example, I can make
MyKeyWord be
colored red, but only if it is outside of the
quotes, like this:
    Robert MyKeyWord said, "Hello there."
but not inside the quotes:
    Robert said, "Hello there MyKeyWord."
I've flailed around with face customization and various attempts at
disabling font-lock-string-face, all without success.
Suggestions for achieving this peculiar customization will be very
welcome. Thanks!