Is there a sound supplication for the return of lost property, or prayer for its return?

There is no established Sunnah from the Prophet, may Allah bless him and grant him peace, with a specific supplication for finding lost things. However, Al-Tabarani narrated a Marfu' hadith that is not authentic, and the supplication was reported as Mawquf from Ibn Umar with a good (Hasan) chain of transmission. A Muslim can supplicate with whatever he wishes, and supplication during prostration or after the Tashahhud is prescribed, but no special prayer should be performed specifically for this purpose.