Edit:
((.(?!\1))+|\1) is used to conditionally match .+ iff a * has been found.
.(?!\1) Matches any character if it is followed by \1. When * has been found then it matches no character, when * is not found it matches every character.
Edit 2:
Formatting to avoid the *s becoming italics :/
^(\⁕?)(\w⁕)(\⁕?)(\w⁕)(\⁕?)(\w⁕) .⁕ ((.(?!\1))+|\1)\2((.(?!\3))+|\3)\4((.(?!\5))+|\5)\6$
Edit: ((.(?!\1))+|\1) is used to conditionally match .+ iff a * has been found. .(?!\1) Matches any character if it is followed by \1. When * has been found then it matches no character, when * is not found it matches every character.
Edit 2: Formatting to avoid the *s becoming italics :/