Twitter Retweet Bot

I want to hire a PHP programmer that knows PHP and Twitter API, oAuth. I need the automatic retweet bot written in PHP and that is working with Twitter oAuth security. If its neccessary, you should also use mySQL. So, for example, when someone tweet something with #twitterbot hashtag, the bot should automaticaly find this tweet (because of preseted hashtag) and retweet it in a structure "RT @User: Text". I am 100% sure that this project is not so difficult. Infact, there are some written bots but they are not working properly. You can also rewrite the old ones.