In need of ideas and experiences to recreate a cocktail

Hello,Few years ago in Paris my SO and I had a cocktail i'd like to try to recreate this week. I even contacted the owner of the bar to make sure of the ingredients, so I have a not too inaccurate idea of what to do.Basically the idea is this : rum or vodka with blackberry liquor, cherry liquor, coke, pepper and a "special ingredient you won't find in commonfolk's retail".Anyway, what I'm interested in is if any of you guys had met something similar, what the "special ingredient" could be and what proportions would you use ? I'm fairly noob in cocktails so I guess more experienced folks' experience would be a good start for me to try !Cheers http://www.reddit.com/r/cocktails/comments/3e47qw/in_need_of_ideas_and_experiences_to_recreate_a/