Create a bridge between Joomla user and iJoomla Guru

I have a client that I am building a small learning site for using iJoomla Guru. There is a feature that creates a certificate the student can click and generate one based on some variables that I am given to populate the cert with. Currently it appears the component only grabs username, firstname, lastname, company and email from the Joomla user. I need to include a custom field that has a certification number they have to have in order to validate the certificate. I tried to create a custom field in Joomla but Guru does not see it and even if it did I would need to create a variable that I could use to populate it on the cert. So I need a custom plugin or something that is connected to these users so they can fill out the field with their certification number and it becomes part of their profile. Then I need a way to call this field as a variable to include on the printable certificate.