Export recognition upon delivery of raw materials for outsourced processing and methods for commission payment

Our company is Korean Company B, and we are trading with Japanese Company A through the mediation of a Japanese trading house. In return, Korean Company B and Japanese Company A pay commissions to the Japanese trading house. However, Japanese Company A has commissioned Korean Company C with outsourced processing and requested that we deliver the raw materials to Korean Company C. Originally, it is correct for Japanese Company A to purchase the raw materials and supply them to Korean Company C, but since both Company B and Company C are Korean companies, they wish to deliver the raw materials directly. (Korean Company C processes the raw materials and then ships them to Japanese Company A.) In this regard, I have the following three questions: 1) In this case, from the perspective of Korean Company B, can this be viewed as an overseas export rather than a domestic sale? 2) Even if the raw materials only move within Korea, can Japanese Company A issue a PO through the Japanese trading house by treating this as outsourced processing trade or similar? (The structure is: raw materials flow from Korean Company B → Korean Company C, and payment flows from Japanese Company A → Japanese trading house → Korean Company B.) 3) If option 2) is not possible, is there a method or legal basis for Korean Company B and Japanese Company A to pay commissions to the Japanese trading house?