Hi.
Assuming the first part of the string is always of the precise format yymmddd followed by a space:
=0+REPLACE(REPLACE(LEFT(A1,FIND(" ",A1)),5,,"/"),8,,"/")
Edit: seeing VoG's solution it appears I may have misunderstood. I presumed that the part in parentheses was also in the cell entry, though perhaps this was just your attempt at clarification?
Regards