Jean-Marie Le Pen vowed to turn up at the FN's national congress in March following the court's decision on Friday.
But the party's general secretary, Steeve Briois, declared that he would not be allowed entry, saying that only fully paid-up members can attend the conference.
So a confrontation seems inevitable.
Judgement with sting in its tail
The court in Versailles upheld a lower court's endorsement of the veteran right-winger's expulsion.
But it also endorsed the lower court's ruling that he must remain the party's honorary president, which gives him the right to sit on some of its bodies, notably the political bureau.
The appeal court even raised the fine the FN must pay if he is prevented from doing so from 2,000 euros for each violation to 5,000 euros and awarded 25,000 euros in damages to the 89-year-old former chief.
It remains to be seen whether the law would interpret attending the congress, to be held in the northern city of Lille on 10-11 March, as part of the honorary president's functions.
But Le Pen appears to think so.
He told the AFP news agency Friday that he intends to go and to appeal to law enforcement officials to help him enter the meeting hall if needs be.
Later in the day, Marine Le Pen said her father "would do anything for a bit of media attention".
Jean-Marie Le Pen was expelled from the party he cofounded in 2015, a victim of his daughter's efforts to clean up its image.
The immediate cause was his repetition of his description of the Nazi gas chambers as a detail in the history of World War II and his defence of Marshal Philippe Pétain, who led the government that collaborated with the German occupation.
But he had been locked in battle with Marine Le Pen and her then-ally Florian Philippot for some time and the expulsion was a sign that their strategy for expanding the party's base had won the day.
It did not put an end to the dispute, however, nor did it end crises within the party.
While Marine Le Pen made it to the second round of last year's presidential election, her performance in the final TV debate with Emmanuel Macron was widely judged disastrous and her vote in the final round, at 33.9 percent, was lower than forecast.
The results of the ensuing parliamentary election, in which the party won eight seats, also disappointed the membership and an internal dispute blew up, leading to Philippot and some of his allies leaving the party to set up their own movement.
There may be further ructions over Marine Le Pen's proposal to change the party's name.
And there are ongoing legal investigations into fake jobs and electoral malpractice allegations.
Honorary presidency may be scrapped
The congress is expected to amend the party's constitution to abolish the post of honorary president, which was introduced in 2011 to allow Jean-Marie Le Pen to retain a title while Marine Le Pen took over the presidency itself.
A poll of the membership showed an overwhelming majority in favour of doing away with the post but it is nevertheless awarded for life.
Scrapping the post "won't stop me being honorary president", Jean-Marie Le Pen commented on Friday. "I won't have the prerogatives any more but I'll keep the title."