Limit number of digits after comma in textbox - excel

Question

I have a textbox in userform which will be filled only with digits, commas, or dots. I know how to restrict use of only those characters. My question is it possible to limit filling value to 2 digits after coma/dot?
So when I enter value like: 1023,456 it would not let me type 6 without any action.
Editted:
I can't get this... I tried testing codes given here: Regex to match 2 digits, optional decimal, two digits However it matches too many things. When I type more then 2 digits after comma it still matches as good string. I used for example:
\d{0,2}(\,\d{1,2})?
[0-9]?[0-9]?(\,[0-9][0-9]?)?
What I am doing wrong?
Private Sub netto_Change()
Dim regEx As New VBScript_RegExp_55.RegExp
regEx.Pattern = "\d{0,2}(\,\d{1,2})?"
If regEx.Test(netto.Value) = True Then MsgBox ("It works!")
End Sub
Edit 2:
Okay, I am really close I got this code: ^[0-9]+[\,\.]?[0-9]?[0-9]$ but one thing is missing. This pattern should also apply to string like: 321, with comma\dot at the end but without anything after that.
What to do?

Answer 1

The Textbox controls (there are at least two: ActiveX and UserForm) have events that can be used to QA the data.
On a UserForm:
Private Sub TextBox1_Change()
' QA text here
End Sub
There are other events, like KeyDown() and Exit() that may work better.

Answer 2

This assumes you have event code to trap after the user completes entry to the TextBox. That code should call the following function. The function will return True if the string is good, False if the string is bad. Your code must decide how to handle False :
Public Function QualCheck(S As String) As Boolean
Dim L As Long, CH As String, I As Long
QualCheck = False
L = Len(S)
For I = 1 To L
CH = Mid(S, I, 1)
If CH Like "[0-9]" Or CH = "." Or CH = "," Then
Else
MsgBox "bad character " & CH
Exit Function
End If
Next I
If InStr(S, ".") + InStr(S, ",") = 0 Then
QualCheck = True
Exit Function
End If
If InStr(S, ".") > 0 Then
ary = Split(S, ".")
If Len(ary(1)) > 2 Then
MsgBox "too many characters after ."
Else
QualCheck = True
End If
Exit Function
End If
If InStr(S, ",") > 0 Then
ary = Split(S, ",")
If Len(ary(1)) > 2 Then
MsgBox "too many characters after ,"
Else
QualCheck = True
End If
End If
End Function
NOTE:
This code does not rely on regEx

Answer 3

I found some time to think and I came up with a different idea on how to cope with that.
First of all I used KeyPress event to prevent input of any characters different then 0-9, comma and dot. To make my code work as I wanted I added code to Change event. If sentence checks whether there is comma or dot in my texbox input. If it is, limits maxlength.
Private Sub netto_Change()
Dim znaki As Byte
znaki = Len(netto.Value)
If InStr(1, netto.Value, ".", vbTextCompare) > 0 Or InStr(1, netto.Value, ",", vbTextCompare) > 0 Then
If netto.MaxLength = znaki + 1 Or netto.MaxLength = znaki Then
Else
netto.MaxLength = znaki + 2
End If
Else
netto.MaxLength = 0
End If
End Sub
Private Sub netto_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger)
Select Case KeyAscii
Case Asc("0") To Asc("9")
Case Asc(",")
Case Asc(".")
Case Else
KeyAscii = 0
End Select
End Sub