Sub Demo()
Application.ScreenUpdating = False
With ActiveDocument.Range
  With .Find
    .ClearFormatting
    .Replacement.ClearFormatting
    .Text = "[^13^l][0-9]{2}:[0-9]{2}[!A-Za-z]@([A-Za-z])"
    .Replacement.Text = " \1"
    .Forward = True
    .Format = False
    .Wrap = wdFindContinue
    .MatchWildcards = True
    .Execute Replace:=wdReplaceAll
  End With
End With
Application.ScreenUpdating = True
End Sub