The DK and desktop TatukGIS Editor contain advanced support for coordinate systems with features to transform (reproject) a vector or raster layer(s) from any coordinate system to any other coordinate system, and save the result to a new file in the new coordinate system. If the coordinate system of the source layer is unknown, use the Editor to rectify (if necessary) and georeference the layer to the desired coordinate system. For guidance, refer to the Editor helpfile information for layer rectification.
The free TatukGIS Viewer can on-the-fly reproject layers from between coordinate systems for viewing only.
If the exercise involves only a few points, another option is to use the free TatukGIS Coordinate Calculator to individually convert the coordinates of each point.