Hello,
I believe you just need a custom field added to registration that your customer will fill out when creating an account. Once the account is successfully created the script will then poll the other website with the patient ID, and update a custom field in Woocommerce to let you know if that customer is already verified.
I do have a quick question though, this list of websites they can verify on, how large is it? Web scraping usually requires that each one be custom coded since they will all likely have different forms and responses. (Also, do any have captcha's?)
Thanks,
Keith