wht do u mean where
just put it under the frame you want it on

if you mean you don't know how the frames work in the replay file then they start at 0 and go upwards so that in a 500 frame replay if you want to go to the frame where the ingame timer would show 100, you'd have to find FRAME 400; in the file
so its pretty much just substracting the frame shown by the timer from the starting matchframes

if you mean something else then i have no idea what you mean