COTABATO CITY -- Another key appointed regional executive resigned Monday to run for municipal mayor as a substitute candidate.Lawyer Mimbalawag Tomawis Mangutara, Jr., who had served for six years as finance director in the Office of the Regional Governor, or ORG, in the Autonomous Region in Muslim Mindanao, will file his substitution documents to the poll body Wednesday, replacing his aunt, Raga Tomawis Beda, an aspirant for the mayoral post in Parang, Maguindanao.Mangutara, also an accountant, is an ethnic Iranun who resides in the municipality, unlike some incumbent municipal elected of