Hummmm
He actually looks like a stained magpie as I have never seen such a faded orange in a harlequin and he is a buck after all
Do you own this rabbit? Can you clarify if he is orange/cream and black or if he's white and black?
Genetically a harlequin is A_ B_ C_ D_ ej_ while magpie is A_ B_ cchd_ D_ ej_
The fastest way to get more would to breed him to a red or fawn (if he's harlequin) or a frosty (if he's a magpie) as you'll get them in the first generation, otherwise breeding to a chestnut ( if a harli) and a chinchilla (if a magpie) and breeding him back to his daughters is the way to go.
Unfortunately the pattern is nearly impossible to replicate as the rabbit you breed him to will have different modifiers and could create a completely different brindling pattern