Code for verifying Belgian IBANS

Question

Can someone help me create a function in Visual Basic for Applications (Excel) for verifying Belgian IBAN numbers? So I can add a list of numbers in Excel and it validates them as TRUE or FALSE.

Example of a Belgian IBAN number:

BE43 1325 3117 7701

I have tried several things before asking for help. I've tried to adjust code I found in an earlier topic on this site, which was:

Public Function VALIDATEIBAN(ByVal IBAN As string) As Boolean
On Error GoTo Catch

Dim objRegExp As Object
Dim blnIsValidIBAN As Boolean

Set objRegExp = CreateObject("vbscript.regexp")
objRegExp.IgnoreCase = True
objRegExp.Global = True
objRegExp.Pattern = "^[a-zA-Z]{2}\d{2}[ ]\d{4}[ ]\d{4}[ ]\d{4}[ ]\d{4}[ ]\d{4}|CZ\d{22}$"



blnIsValidIBAN = objRegExp.Test(IBAN)
VALIDATEIBAN = blnIsValidIBAN

Exit Function

Catch:
VALIDATEIBAN = False
MsgBox "Module: " & MODULE_NAME & " - VALIDATEIBAN function" & vbCrLf & vbCrLf _
    & "Error#:  " & Err.Number & vbCrLf & vbCrLf & Err.Description
End Function

I've been trying to modify by adjusting:

objRegExp.Pattern = "^[a-zA-Z]{2}\d{2}[ ]\d{4}[ ]\d{4}[ ]\d{4}[ ]\d{4}[ ]\d{4}|CZ\d{22}$"

I started with the obvious, removing eight positions of the check like this:

objRegExp.Pattern = "^[a-zA-Z]{2}\d{2}[ ]\d{4}[ ]\d{4}[ ]\d{4}|CZ\d{22}$"

This way I can get the code in Excel to "verify" as true or false, but I think by just removing the positions from the code I also remove the code's ability to perform an actual verification on the IBAN number.