I am a parent and assistant coach at a feeder program. Having been a high school football and wrestling coach, I found it critical to my success as a program to be involved heavily with our youth programs. In football, assistant coaches volunteered time to go to practices to meet the coaches and we asked that they ran some of our plays. The middle school programs ran everything the same. For wrestling, it was even bigger as we were able to start teaching our system early. That has begun paying dividends as some of those kids are now in high school and are excelling. Our feeder program's high school does absolutely nothing with us. There are no special events involving the younger kids with the Varsity nor are there any real perks to the program. How do you get the high school to be involved? Conversely, what would you expect as a high school coach from your feeder program in terms of involvement with the high school program?
This is tough but it starts by having a strong "feeder" program that has purpose. This will allow you to approach the varsity coach and have a meaningful discussion. Also keep in mind most high school budgets for baseball are non-existent and staff is sometime difficult to procure. Consider also the additional burden an unstructured feeder program can create for the varsity coach. The best advice I can give is to do some research, reach out to the coach and get a dialogue started as it will take some time to get a good footing and relationship built.