The warrant you receive must put you on reasonable notice of the crime of which you are accused, meaning that typographical errors and the like are not grounds for dismissal unless they are so egregious as to deprive you of knowledge of what you need to defend. The law also allows the Commonwealth to amend the face of a warrant to correct errors such as in your date of birth.
At trial you can expect the Commonwealth to introduce evidence of your true age, possibly through testimony of the arresting officer as to statements you made or through a properly authenticated public document such as your DMV record.
DUI cases are complicated, though, and you may have many viable defenses. You should speak with a Virginia lawyer who has experience defending DUI cases and who can speak intelligently about the city or county in which you are charged.