Ok, this is admittedly the long way round. Locate a person (must be humanoid) who excels in persuasion. Preferably someone with not only a high charisma, but expertise. Could be helpful if they are already something like a noble or a magic item trafficker. Get hold of some of their hair blood, or a thumb or something through either offering them money or skulduggery. Use that to create a simulacra of them. Send them off to get it.