trimming video and stretching it

i been trying for the past 6 hours on cutting a specific part of a video using the set in and set out points. However on the timeline i want to add the time coding ping pong expression so it can stutter back and forth to the music, but when i stretch it, it adds the rest of the video i do not want from the clip. does not repeat with the loopOut function. What am i doing wrong here. I got the loop to work with a full clip, but i can't get it done with this one. please help thanks

thanks i have tried this as well. tried again and it still keeps playing the footage after the cut out when i time stretch it. do i need another program to chop it up?

i am a newb and what you said sounded french to me lol. sorry but can you explain thanks

thanks that worked. however as i did this, the timeline now starts from 00860 instead of the beginning,i cant seem to get back to that start. I used the loopout function with pingpong but it does not keep looping to the extended clip. it stops in the middle instead of looping for the entirety of the timestretch.

thanks well i learned the basics somewhat. learned all about the loopouts and the basic functions but -b -n was not covered there. Or in this case how do i get back to zero? i deleted the clip so i can do it all over again and did undo as back as i could. but the timeline stills shows the beginning as 00860. can't seem to get back to zero even if i entered it on the time on the left. i am almost done with this video, just the looping part of that clip needs to be added. i have the intro with a sun coming up and back down with the pingpong attribute and the title. that worked flawlessly. this clip is the only thing giving me issues here. i also did the expressions for the soundkeys to make it move with music. I did not save before i did the -n and -b so i really don't want to start over.

You are welcome.
Ok I'll be waiting for your result :)