How to modify Borneo RSO within your Arcgis environment? Please follow steps given below :

Note: This tutorial is based on Arcgis 9.3. Same method applied for ArcGIS 10.++.

1.Run Arcmap and go to View > Data Frame Properties

2.In Data Frame Properties window go to Select a coordinate system: box, then browse to Projected Coordinate System > National Grids > Malaysia > Timbalai 1948 RSO Borneo Meters, then click Modify button.

3.Change False_Easting and False_Northing parameter value into 2000000 and 5000000. Rename it into BRSO.

4.Once you clicked OK, it will appear in custom directory. You can save it by clicking Add To Favorites button.

5.Or you can create a *.prj which is a default projection file for ESRI product. Use your favorite text editor such as notepad or notepad++ to write ESRI WKT format. Copy the ESRI WKT format file below:

PROJCS["Timbalai_1948_RSO_Borneo_Meters",GEOGCS["GCS_Timbalai_1948",DATUM["D_Timbalai_1948",SPHEROID["Everest_Definition_1967",6377298.556,300.8017]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Rectified_Skew_Orthomorphic_Natural_Origin"],PARAMETER["False_Easting",2000000.0],PARAMETER["False_Northing",5000000.0],PARAMETER["Scale_Factor",0.99984],PARAMETER["Azimuth",53.31582047908623],PARAMETER["Longitude_Of_Center",115.0],PARAMETER["Latitude_Of_Center",4.0],PARAMETER["XY_Plane_Rotation",53.13010235415598],UNIT["Meter",1.0]]

Copy and save it as ‘Timbalai 1948 Borneo RSO.prj’ inside the ArcGIS Coordinate Systems directory, in my case it is in “C:\Program Files (x86)\ArcGIS\Coordinate Systems\Projected Coordinate Systems\National Grids\Malaysia”.

Happy mapping!