Okla. Stat. tit. 58 § 348
If the executor or administrator doubts the correctness of any claim presented to him, he may enter into an agreement, in writing, with the claimant, to refer the matter in controversy to some disinterested person, to be approved by the judge of the county court. Upon filing the agreement, and approval of the judge of the county court, in the office of the clerk of the district court for the county or judicial subdivision in which the letters testamentary or of administration were granted, the clerk must, either in vacation or in term, enter a minute of the order referring the matter in controversy to the person so selected; or if the parties consent, a reference may be had in the county court; and the report of the referee, if confirmed, establishes or rejects the claim, the same as if it had been allowed or rejected by the executor or administrator and the county judge.
Okla. Stat. tit. 58, § 348