Sub Test_BoldText()
Dim oRng As Range
Set oRng = ActiveDocument.Range
  With oRng.Find
    .ClearFormatting
    .Forward = True
    .Wrap = wdFindStop
    .Format = True
    .MatchWildcards = True
    .Replacement.ClearFormatting
    'Find text before first tab or colon and format bold
    .text = "([a-zA-Z0-9][!^13]@)([^t:])"
    While .Execute
       If oRng.Characters(1).Start = oRng.Paragraphs(1).Range.Characters(1).Start Then
         oRng.Select
         oRng.Font.Bold = True
         If Not oRng.Characters.Last.Next = vbTab Then
           oRng.text = Replace(oRng.text, ":", vbTab)
         Else
           oRng.Characters.Last.Delete
         End If
       End If
    Wend
  End With
  End Sub

Sub BoldText()
Application.ScreenUpdating = False
With ActiveDocument
  With .Range
    .InsertBefore vbCr
    With .Find
      .ClearFormatting
      .Replacement.ClearFormatting
      .Forward = True
      .Format = False
      .Wrap = wdFindStop
      .MatchWildcards = True
      .Text = "^13[!^13]@[^t:]"
    End With
    Do While .Find.Execute
      .Start = .Start + 1
      .End = .End - 1
      .Font.Bold = True
      .Characters.Last.Next = vbTab
      .Collapse wdCollapseEnd
    Loop
  End With
  .Range.Characters.First.Delete
End With
Application.ScreenUpdating = True
End Sub