There may well be a simpler way but this works
VB Code:
Const TIME1 = "40:30"
Const TIME2 = "113:47"
Dim strParts1() As String
Dim strParts2() As String
Dim intMinutes As Integer
strParts1 = Split(TIME1, ":")
strParts2 = Split(TIME2, ":")
intMinutes = CInt(strParts1(1)) + CInt(strParts2(1))
If intMinutes > 59 Then
MsgBox CInt(strParts1(0)) + CInt(strParts2(0)) _
+ (CInt(strParts1(1)) + CInt(strParts2(1))) \ 60 _
& ":" & Format((CInt(strParts1(1)) + CInt(strParts2(1))) Mod 60, "00")
Else
MsgBox CInt(strParts1(0)) + CInt(strParts2(0)) _
& ":" & Format((CInt(strParts1(1)) + CInt(strParts2(1))), "00")
End If