What is the french statute of limitations for enforcement of an
equitable accounting judgment?

A French court entered a default judgment (ordering an equitable
accouting to determine damages) against a U.S. citizen with French
passport many years ago.  The plaintiff is now trying to enforce the
judgment in a state which will apply the French statute of limitations
on enforcement to determine if it is timely.  In any case, the delay
in seeking the accounting will make one impossible now.