ORS § 20.150
In an action, suit or proceeding prosecuted or defended by an executor, administrator, trustee of an express trust or person expressly authorized by statute to prosecute or defend therein, or in which a party appears by general guardian, conservator or guardian ad litem, costs and disbursements shall be recovered or not as in ordinary cases, but if recovered shall be chargeable only upon or collected from the estate, trust fund or party represented or for whom appearance is made, unless the court or judge thereof shall order such costs and disbursements to be recovered from the executor, administrator, trustee, person, guardian or conservator personally for mismanagement or bad faith in the commencement, prosecution or defense of the action, suit or proceeding.
ORS 20.150