Target the player and use the command #bind
This command calls the following code, in case you don't have it for some reason.
Code:
void command_bind(Client *c, const Seperator *sep)
{
if (c->GetTarget() != 0 ) {
if (c->GetTarget()->IsClient())
c->GetTarget()->CastToClient()->SetBindPoint();
else
c->Message(0, "Error: target not a Player");
} else
c->SetBindPoint();
}