A command is saying like “hey Samantha go open the door.” Therefore you can always say “have her open the door”. Pronouns replace a proper noun so instead of saying Samantha you say her or she. You use these in a command by saying the pronouns. They work together by instead of saying the nouns proper name you say their pronouns to do the command. Proper nouns are more formal and direct while pronouns are indirect and informal. You don’t always have to say the proper noun when saying a command so that is how pronouns come into use. Therefore that is how you have a pronouns and commands work together.
