Custom Validation on Infusionsoft webform

Hi (First time poster here)

Is it possible to add custom validation to an Infusionsoft webform? For example, lets say I want to ensure that any phone number submissions, must start with a 0. Can I have a validation message which checks this and prompts the contact if it is not entered correctly?

If it is possible, I’m not a developer (I will need to brief someone) is there a certain code that needs to be used. Would it be coded on the Infusionsoft webform itself, or on the website it’s embedded? Note it is being embedded using the HTML feature.

The code would live on the web page that the HTML form resides (typically). Form validation on the web is typically written in JavaScript/jQuery or HTML5.