making a reply bot that reacts to tags (read body)

https://i.imgur.com/SiGM8ak.png 

so theres a server that i use that has a post in their introduction(in a channel you cannot reply to), and it has an emote react matched to a number of activities. such that if you want to participate in a group activity, you react with that emote matching the activity, for example activity1, you react smily face etc. and if someone in any of the server's other chat channels types @activity1, then all people that reacted with a smily face to that initial post get a notification to that message. verry usefull for forming groups for specific activities. i have been searching all over on how to do this in a server and have found nothing that does exactly this.

it would be better for my application of this function if, instead of you getting a notification to the message in the channel, that you got a specific private message sent to you. such that if you react that you are interested in being notifyed when someone is starting to make a group, just for the sake of the example, say its bowling. so you reply with the bowling ball emote because you want to be notifyed when someone is trying to form a group for bowling. so when someone is talking in a chat channel, and types @bowling, and then states the details of the group activity following the tag. then once this tag is posted in chat, a bot will automaticly send anyone who replied to that initial post with a bowling ball, the body of the messaage following the tag.

example initial post in no reply channel:

reply to be messaged when someone is forming a group for the following activities
(the (number) is meant to represent diffrent emotes)
@**bowling** (1)
@**fishing** (2)
@**skiing** (3)
etc

bla bla bla rules bla bla bla
(emote reactions shown below with the number next to the emote being the number of people who replies with this emote)
(1)277 (2)143 (3)742

someone talking in a channel called group activity forming:

@**bowling** we are going bowling tonight at 7pm at the bowling alley on broadway blvd and 5th ave.
react to this message with a smily face emote if you are going to be able to attend. (this person includes the message hyperlink to this message so people can quickly navigate to the message and reply for rsvp)

and evryone who replied (1) to the initial post will recieve this message body, probablyt including the (@**bowling**), in their private messages.

i know this isnt the most simple thing to generate, but i really want to get this going on my server.

please help! thankyou