To encrypt to someone else's key that has an ADK, just import both the other person's key, and their ADK, sign both to have both marked as Verified.
If you have a local ADK that has to always be encrypted to, this will be done by your organization if you are in a settings managed by a PGP Universal Server. If not in such setting and there is some other key your organization mandates that all encryption also be encrypted to, add that key to your Master Keys in Options. However, realize that any key in the Master Key list, is a key that all email encryption, all file encryption, all virtual disks, etc. will also be encrypted to. So the owner of this key can decrypt any and all encryption you ever do. Typically, the only key someone adds to the Master Key list, is their own key, ensuring that he/she can always decrypt any encryption he/she does.