Pakistan passport holder applying for PRC visa

The Pakistan passport holder resides in Singapore and is applying to visit our Shanghai office for business meetings/workshops etc. I understand Pakistan passport holder requires a Ministry of Foreign Affairs invite to apply for it in Singapore with the Chinese Embassy. We have been asked by the MFA in China to submit a Registry of Company Report - this we have done. However they have asked they this document be "approved" by the local Chinese Embassy here in Singapore. Can this be done by the local Chinese Embassy here? If so, where should be bring the document to please?