Nark and Little Toe,
Nark: "In your example with "the King / His Highness" the identification is only clear because the two expressions are known as equivalents in the reader's/hearer's usage." ... Littletoe: "though I appreciate that it can be translated the Lord Holy Spirit and the context seems to be predominantly filled with activity of the same."
This is the point ... and maybe I have erred in strict ancient Greek grammer, but overlaid a "known equivalent." Notwithstanding, the real use and purpose of Acts 13:2 was to show that the Holy Spirit is a person who speaks and exercises his own will. I will still look for the source reference which gave me the view that Lord and Holy Spirit were the same, because of the wording using the subordinate clause. When I do, I will post it. Doctrinally, they are the same, for the Holy Spirit is known as Lord and giver of life. However, doctrine should never dictate rules of grammer.
Thanks,
Jim Whitney