でいらっしゃいますか

are you...? / is ...?

→ だ
phrase Rare #32,373
are you...? / is ...? A very polite, honorific way to ask whether someone or something is a particular identity, status, or condition. It is used instead of ですか when showing respect.
JA: 田中さんでいらっしゃいますか。
EN: Are you Mr. Tanaka?

旦那様お帰りでいらっしゃいますか

Has my husband returned home?

— 紅夢 (1991)

クラウチさんでいらっしゃいますか

Are you Mr. Crouch?