In all Juvenile Delinquency and Children in Need of Services matters brought pursuant to RSA 169-B and RSA 169-D respectively, the appearance of counsel for the child shall be deemed to be withdrawn thirty (30) days after the date of the Clerk’s notice of the dispositional order unless a post-dispositional motion is filed within that thirty (30) day period or the court otherwise orders representation to continue. Where a post-dispositional motion is filed within thirty (30) days, the appearance of counsel for the juvenile shall be deemed to be withdrawn thirty (30) days after the court rules on said motion. Where the court otherwise orders representation to continue, the order shall state the specific duration and purpose of the continued representation. Counsel for the juvenile shall be deemed to be withdrawn immediately at the end of the ordered duration.