Is there a way to count digits entered by the get digit string to verify the correct number entered?
You talking about UCCX / IP IVR? If so then you can take the input and just use a .length() method on it and assign it to a variable or something.
inputlength_variable = input_variable.length()
For CVP if you use a GD microapp you can then just do a len(Call.CallerEnteredDigits) immediately after the CED block and do whatever you want to it.