I guess you are talking about emote.
During a fight type /em <your text here>
For editing a replay:
-Open the replay you want to add text in, in notepad.
-Look for the frame you want to add text in, let's say, frame 50.
-Find the line of frame 50 and add the following in a new line under "ANGVEL" line:
EMOTE 0;<Your text here>
For Uke:
EMOTE 1;<Your text here>
-Go to file --> Save. Run the replay and you will see the your tori emote the text you entered there.
I hope i helped.