in the client when you run replays the frames count down to 0 while in the text file of the replay it counts up from 0, so in the txt file FRAME 0 is frame 500 in a replay with 500 frames, and so on

if you have a 500 frames replay and want an emote to appear on FRAME 400, you go on the txt file and go under frame 100 (it should say something like FRAME 100; 0 0 0 0) and at the end of that frame type EMOTE 0;[whatever you want to say]

heres what it looks like for the replay i attached where i have an emote on frame 490 that says A