It is impossible to give you any guidance as to how to handle this situation without knowing the reason for the outstanding warrant. The fact that there is an outstanding warrant tells you that in the Court's opinioin you have failed to do something the Court ordered you to do.
As a practical matter, you need to turn yourself in, figure out what the problem is and fix it. In addition, since a warrant has been issued and you will have to appear before the Court to resolve the issue at some point, you should retain an experienced Virginia DUI & Criminal Defense Lawyer to assist you with this matter.
DISCLAIMER: This answer is provided as general information and is not to be considered legal advice, nor does it constitute the creation of an attorney-client relationship.
For important answers to other Frequently Asked Questions about DUI, Criminal and Traffic Offenses in Virginia, visit my website at: http://www.tkevinwilsonlawyer.com/faq.cfm.
T. Kevin Wilson, Esq.
The Wilson Law Firm
DUI, Criminal & Traffic Defense...When Results Matter
9300 Grant Avenue, Suite 301
Manassas, Virginia 20110