The challenge is to have Charlemagne conquer Spain, or a big central chunk of it from the Ummayyads. Even more points if it is permanently under the same crown as West Francia ever after.
It's the OTL Spanish March more or less this? I suppose they could push it all the way to the Ebro.
Perhaps they could negotiate a relationship of vassalage and protection from Asturias.
Tagus river or bust man, with prolonged integration of Asturias or whatever else is in the north to west Francia.
Spain goes Italy.
Another timeline in which Portugal does not exist. I guess that the western half of the peninsula (at least) would be more unified.
Spain goes Italy.