Auto Reply to a Specific User's Tweets

Ive been using FL for months and i already talked to FL support and they told me how to do it according to them which did not work at all. Is their anyway to do as the title says? Even if paid?

What I want, some tool that would tweet a predefined tweet the moment that a certain's users tweet. Ex: https://twitter.com/patrioticpepe/status/801110691859959812 (He's pretty much always the first reply under his tweets)

Did you find anything for this? I am interested in this as well.

Try http://twittermoneybot.com/.

IFTTT.com should be able to do that. I have two accounts and one retweets the other using IFTTT.