xenForo Expert needed

I need a "xenForo" expert to handle a small thing that I want to do manually through custom PHP code. here is the details>>>>> I have following things 1) UserName 2) Topic Name 3) Title 4) Post Content So, you have to check if user exists? if no, create new user by provided "UserName". So, you have to check if TopicName exists? if no, create new user by provided "Topic Name". So, you have to check if PostContent exists? if no, create new user by provided "Title". Insert data into "xenForo" database. and that's it. I know, its a small task But, still I want to see some "xenForo" samples. thank you!