Prestashop programmation

General information for the website: We sell Herba Life products
Description of requirements/features: On the HERBA site, I have installed a module: zSMS Notification.

This module works only when the Registration Procestype is the Standard account creation: create account + make address.
(See Preferences -> Customers)
The field mobile phone must be filled in to be able to send an automatic SMS.

2 questions
1/
Is it possible to adapt the validate file, so that customers are forced to fill in their mobile phone number as follows:
0032 475222 222.
Normally they fill in 0475222222
So the first 0 must be deleted, and the mobile number must be preceded by 0032 (the international number for Belgium).

2/ My client prefers the Registration procestype to be only: account creation.
So customers do not have to fill in their address immediately.
Is there a way to add the mobile phone number record to this short registration and also make the sms-module work?
Extra notes: