If the 8379 form gets me my share of the joint refund back, will that amount get added back on my ex's child support or will he owe that amount in back taxes next year?

My husband and I filed jointly and all of our tax return went to his child support arrears. If I file an 8379 form and the IRS gives me my share of the refund back, will that amount get added back on to what my husband owes to child support or will he owe that amount in back taxes next year?  He lives in another state now (we're getting divorced), so how will he be notified about the 8379 refund I will receive?