The "Explanatory Notes on Geodetic Datums in Hong Kong" contains information about Geodetic Datum, Map Projection and Grids, Vertical Datum and Conversion of Coordinates.
You can set the "Datum Transformation and Transformation Parameters" (The "7-parameters") for conversion of coordinates between HK 1980 Grid Systems and WGS 84 Coordinates for your receivers and applications.
The Direcção dos Serviços de Cartografia e Cadastro (DSCC) of Macao Special Administrative Region Government and the Survey and Mapping Office of Lands Department of Hong Kong SAR Government have completed a joint GNSS survey to establish the transformation relationship between the Macao Geodetic Coordinate System and the Hong Kong Geodetic Coordinate System.