Does 外公役 mean public servant?


I am just translating the Japanese wikipedia chart of the servants in the Ooku
of Edo Castle. I have been doing okay until I got to the omote-dzukai part.
This is the original:

> 表使 (おもてづかい) 外公役。御年寄の指図で物資調達を広敷役人に要請していた。

I just need help with 外公役 as I am not too sure how I would translate that. Is
it public servant or is it something like "role of outside relations"? It just
does not sound right in this context (The sentence afterward being "Under the
orders of the o-toshiyori, in charge of requesting the Hiroshiki official to
procure supplies")

