Sub TimecodeEditor()
' Paul Beverley - Version 22.10.14
' Increment/decrement timecode in a file

Selection.Expand wdParagraph
Selection.Collapse wdCollapseStart
Selection.End = Selection.End + 5

myText = Selection
wasStart = Selection.Start
wasMins = Val(Left(myText, 2))
wasSecs = Val(Right(myText, 2))

userInput = InputBox("+/- seconds?", "TimecodeEditor")
extraSecs = Val(userInput)

If extraSecs = 0 Then
  myResponse = MsgBox("Please type + or -, and a number of seconds", _
      vbExclamation, "TimecodeEditor")
  Exit Sub
End If

' Calculate new timecode
myNewSecs = wasSecs + extraSecs

secsNew = myNewSecs
minsNew = wasMins

If myNewSecs < 0 Then
  secsNew = 60 + myNewSecs Mod 60
  minsNew = wasMins + Int(myNewSecs / 60)
End If

If myNewSecs >= 59 Then
  secsNew = myNewSecs Mod 60
  minsNew = wasMins + Int(myNewSecs / 60)
End If

minsText = Right("0" & Trim(Str(minsNew)), 2)
secsText = Right("0" & Trim(Str(secsNew)), 2)
newTime = minsText & "." & secsText

myResponse = MsgBox("You typed " & userInput & vbCr & _
     "New timecode = " & newTime & " OK?", _
      vbQuestion + vbYesNo, "TimecodeEditor")
If myResponse <> vbYes Then
  Beep
  Exit Sub
End If

Selection.TypeText newTime

' Go and find the first occurrence
Set rng = ActiveDocument.Content
rng.Start = Selection.End
With rng.Find
  .ClearFormatting
  .Replacement.ClearFormatting
  .Text = "^p^#^#.^#^#"
  .Wrap = wdFindStop
  .Replacement.Text = ""
  .Forward = True
  .MatchWildcards = False
  .Execute
End With

Do While rng.Find.Found = True
' Note where the end of the found item is
  endNow = rng.End
  rng.Start = rng.Start + 1
  myText = rng.Text
  
  wasMins = Val(Left(myText, 2))
  wasSecs = Val(Right(myText, 2))
  
  ' Calculate new timecode
  myNewSecs = wasSecs + extraSecs
  
  secsNew = myNewSecs
  minsNew = wasMins
  
  If myNewSecs < 0 Then
    secsNew = 60 + myNewSecs Mod 60
    minsNew = wasMins + Int(myNewSecs / 60)
  End If
  
  If myNewSecs >= 59 Then
    secsNew = myNewSecs Mod 60
    minsNew = wasMins + Int(myNewSecs / 60)
  End If
  
  minsText = Right("0" & Trim(Str(minsNew)), 2)
  secsText = Right("0" & Trim(Str(secsNew)), 2)
  newTime = minsText & "." & secsText
   
  rng.Text = newTime
  ' Be sure you're past the previous occurrence
  rng.Start = endNow + 5
  rng.Find.Execute
Loop
Beep
End Sub