From a bash script, send commands to a terminal window

I need to run a script which will run many similar commands inside another terminal window (which has a app launched and ready to receive commands).

And the command should be sent to the open terminal that has the app but inside the loop, a new terminal window opens up every time, instead of the commands to be sent to the app in the first terminal.

So far I'm here:

#!/bin/bash

echo "Let's see what we can do";

gnome-terminal -e "./launch.sh"; 
sleep 3s;    
#launched the app which needs to recieve the commands

number=0
while [ "$number" -lt 2 ]
do
        number=`expr $number + 1 `;
        gnome-terminal -e "sample_command -i" "$number";
done

echo "finished";