Cut easier and faster in Source.

Hi, I need some help.


I am editing a video project related to Swedish sign language to be used in a research experiment. Part of this project is to generate a large number of small clips (>1000) consisting of one sign. In order to make the process more effective, I would like to have your help. I am using Adobe premiere pro.

The problem:
Each sign produced is usually about 2-3 seconds. But each clip should be exactly 4 seconds. I.e. >1000  4-sec clips consisting of signs (which is 2-3 secs) are to be delivered

In normal cases, I usually use tools Mark in (I) and Mark out (O) to mark in Source and then click on Insert (,) so that each clip ends up in Timeline. But with 1000 clips to generate, it would take a lot of time if you have to do it manually. I could write +4 seconds in Playhead position but that takes a lot of time too. Do you have better solutions to automatize this further so that I can save time when cutting the files so that it is always exactly 4 seconds. I was wondering if I could "lock" Mark in and Mark out so they are always a 4 seconds "sequence" block to clip with? I hope you understand what I mean.

/Joel