The functions string.Format or StringBuilder.AppendFormat are two very usefull functions for formatting strings and increasing the readability of your .NET code. The Format function in VBA unfortunately works in a quite different way than the string.Format function in .NET. As far as I know there is no built-in function in VBA to acomplish the exact same as string.Format. In VBA the functionality can be achieved the following way:

' Format string using the .NET way
Public Function StringFormat(ByVal strValue As String, ParamArray arrParames() As Variant) As String
    Dim i As Integer

    ' Replace parameters  
    For i = LBound(arrParames()) To UBound(arrParames())
        strValue = Replace(strValue, "{" & CStr(i) & "}", CStr(arrParames(i)))
    Next
   
    ' Get the value    StringFormat = strValue
End Function