If u want to just see a pos in game (to decide if u like it or not, for example), just click on "load" button:
If u want to add a pos to the quick access menu, u need to open a setting file for animtools (..\Loader5.45\Settings\animtoolsV27settings.txt, or smth like this) and scroll down to this segment:
here u can add and remove positions, more details are in file itself and on the screenshot. Just don't forget to move your pos files in
"..\Loader5.45\Settings\animtools_positions" folder