This logic seems to work (used Excel to test)
You'll need to integrate into your own application / user forms
Option Explicit
'DDMMYY-abcd
'a = 0,1,2,3 then born in 19YY
'a = 4,9 if YY < 36 then born in 20YY, if YY > 36 born in 19YY
'a = 5,6,7 if YY = 36 then born in 2000
Sub CPRtest()
Dim s As String
Dim DD As Long, MM As Long, YY As Long, A As Long
'textbox1
s = "231117-5704"
DD = Mid(s, 1, 2)
MM = Mid(s, 3, 2)
YY = Mid(s, 5, 2)
A = Mid(s, 8, 1)
Select Case A
Case 0, 1, 2, 3
YY = 1900 + YY
Case 4, 9
If YY > 36 Then
YY = 1900 + YY
Else
YY = 2000 + YY
End If
Case 5, 6, 7
If YY = 36 Then
YY = 2000
Else
YY = 2000 + YY ' ?????????????
End If
End Select
'textbox2
MsgBox DateSerial(YY, MM, DD)
'textbox3
MsgBox DateSerial(YY + 2, MM + 11, DD)
End Sub