Sub MoveBlockToBeginningOfSentence()
  Dim aRngMove As Range, aRngStart As Range
  Set aRngMove = Selection.Range
  If aRngMove.Characters.Last <> " " Then 'ensure the selection includes a space at the end
    aRngMove.MoveEndUntil cset:=" "
    aRngMove.MoveEnd Unit:=wdCharacter, Count:=1
  End If
  Set aRngStart = aRngMove.Sentences(1)
  aRngStart.Characters(1).Case = wdLowerCase
  aRngStart.Collapse Direction:=wdCollapseStart
  aRngMove.Characters(1).Case = wdTitleWord
  aRngStart.FormattedText = aRngMove.FormattedText
  aRngMove.Delete
End Sub