Find one word but not another anywhere after the 1st word

[RPrinceton]

Hello,
I want execute a find that: Finds a text argument but does not contain the second text argument i.e., If A found and B not found, then true.
I've searched the forum and this answer comes close.
word1(?! word2)

It assumes that word2 follows immediately. How is this coded to say the second word can occur anywhere after the first word?
Thank you advance.
Regards,
RPrinceton