Twitter Textmining User Count

Hello, i am a Newbie and work with rapid miner for education. No i have a question where i need help:

I have to textmining twitter by a special keyword. It works easy. But now i want to select only the user, which post more than 3 tweets in the selection. So how i have to build in a querry or similar? And how can i sort them in the result from most tweets to only one tweet?

I try some different solution but i did not find a answer...

Best regards and many thanks