a waiver of indebtedness, in effect, challenging the indebtedness and, therefore, he is not a claimant under section 5100. In Barger the Court stated: The statute at issue in this appeal is found in chapter 53 of title 38 of the U.S.Code, which concerns special provisions relating to VA benefits. The statute contains its own notice provisions, which, as the Court has held herein, the Board did not misinterpret. The notice and duty-to-assist provisions of the Veterans Claims Assistance Act of 2000, Pub.L. No. 106-475, 114 Stat.2096 (Nov. 9, 2000) (VCAA), which the Secretary argues generally should require a remand of this matter, are relevant to a different chapter of title 38, and do not apply to this appeal. See generally Smith (Claudus) [v. Gober], supra[, 14 Vet.App. 227 (2000)] (<HOLDING>). Barger, 16 Vet.App. at 138. The underlying
holding that where attorney successfully represents a va claimant before this court  the secretary is obligated under certain circumstances to pay directly to the attorney 20 of the pastdue benefits awarded on the basis of the claim or application for benefits underlying the issues successfully appealed to this court recognizing that no guarantee of payment exists even if administrative expense allowed holding that vcaa did not affect federal statute that prohibits payment of interest on past due benefits holding that vcaa did not affect issue of whether federal statute allowed payment of interest on pastdue benefits holding that where payment toward judgment was for less than the total amount of principal and interest  owed that payment then did not terminate the accrual of interest on the remaining principal