Well, you did have to be Dutch and survive the peninsular war for about 4 years.
Napoleon ordered every battalion in Spain to give one veteran for the new Old guard, in 1813. This included two batallions of the 130eme de ligne, which used to be 1st bat, 2de ligne and 2nd bat, 4de ligne, of the Dutch army They were incorporated into the French army, and seen as French, in 1810. And as they had been in Spain since 1809, they stayed there.
I found one of those two men in the Roll call of a militia batallion in the Waterloo campaign.