Fathers day for dads who can't see their child?

It's fathers day soon and I know it's going to be difficult for my partner. His ex has stopped all access to his son and I know he misses him dearly. It's heartbreaking to see him hurt and he's tried writing letters, phoning and calling to the house but all is ignored or the police get involved on the grounds or "harassment" even though he's done it all civilised and non threatening. It's going to court. Anyway, I would hate for fathers day, for him, to be ignored. Is there anything I can do aside from be there? He is fantastic with my child so imagine he'd be even more so with his own. It's disgusting for a mother to use her child as a pawn but it would seem fathers count for nothing in UK law.. I'd appreciate any tips for a nice gift or day that doesn't ignore him on this day. Hope I make sense!