A person attending as a witness under a summons not covered by § 17.1-611, whether he is a witness from within or without the Commonwealth, shall be reimbursed for his daily mileage as prescribed in § 2.2-2823, and expenses for the tolls. On his oath an entry of the sum he is entitled to and for what and by what party it is to be paid shall be made: (i) by the clerk of either house or a committee of the General Assembly when the attendance is before such house or committee and (ii) in other cases by the clerk of the court in which the case is or the person before whom the witness attended. When the attendance was on behalf of the Commonwealth before a court, the entry shall be made upon the minutes of the court in which the case is docketed. A witness from outside the Commonwealth in any civil action may be allowed the same mileage and attendance fee as any other witness in any such action. However, no sums for attendance and mileage shall be allowed a witness from outside the Commonwealth, in any civil action, unless the judge of the court determines and certifies that the witness is a material witness in the matter for which he appeared. The court may allow such mileage and attendance fee or any portion thereof as the court may determine to be reasonable under the circumstances of the case. A witness summoned to attend in several cases may have the entry made against either of the parties by whom he is summoned, but no witness shall be allowed reimbursement for his attendance in more than one case at the same time. Every witness who qualifies as an expert witness, when compelled to attend and testify, shall be allowed such compensation and mileage as the court may, if requested in its discretion, order without regard to any limitation described above, but the same shall be paid by the party in whose behalf he shall testify.