Forums Scripts & Popups get command to write to file

Hello, i have been searching and looking through the forums and tried different things, but i can't get the write function to work so i am asking for help now.

I am trying to make a small script that if someone writes "!command text" it saves the nick and text to a text document, but i can't seem to get it to work and i'm not sure where to put the file and the script, can someone help me?

So i got it to write it to a .txt now, but is it a way to filter out what's been said, trying to make it work for a streamer where people could guess stuff, so if multiple persons guess the same thing they could be put into a group in the document so it's easier to search for that guess?