details about building new inbound interface for payments confirmation file(.csv format)

we are building new inbound interface for payments confirmation file(.csv format) which we are going to receive from third party system bank saying which payments are accepted and which are rejected is. we needs to import these transactions to CE_STATEMENT_HEADERS_INT and then to base tables CE_STATEMENT_HEADERS_INT, CE_STATEMENT_LINES_INTERFACE. please guide us the import program , sample program details, sample plsql code i can use to understand. and also wanted to know how Bank Account Number from CE_STATEMENT_HEADERS_INT table is mapped to which column of the base tables. please suggest details or any notes exists to build this inbound interface.