Welcome to Graybeardoutdoors mndeer. I would say you SHOULD be about 1" high at 25 yards to hit dead on at 100 yards BUT the only way to know for sure is to try it out. All guns are different and some do strange things at 100 yards. You may even need to be an inch or two low at 25 yards depending on the height of your scope above your barrel and other factors.
Is this all you have access to (a 25 yard range?)