おしい！！(nearly) "１１月２１日から１１月２４日まで、いつがよろしいでしょうか" We need to have 'が' after the inanimate subject. Almost good. But I'll say; 'アポイントメントをいただきたいのですが、11月21日から11月27日ではいつがご都合よろしいでしょうか？' If you wanna subject like "I would like to make an appointment", ''アポイントメントに関して'' is OK. But please be careful, Japanese has three type of honorific. Even it's confusing for Japanese. If you'll show off the perfect skill, probably they'll believe that you have enough money to hiring the translator, or Japanese staffs. That's finger crossing they don't reply it in Japanese.