I assume you are referring to the CADSymbols add-on that was part of the bundle.
Unfortunately, CADSymbols does not directly interface with DesignCAD.
That doesn't lessen the value of the symbols, it just makes them a bit harder to get them into DesignCAD. Here is what you have to do:
1) in the CadSymbols program, choose either 'DWG 3D' or 'DXF 3D' as the 'Target'.
2) Pick each symbol that you want to use, and click 'Output'. The dxf or dwg file will be created in whatever folder you select. Take note of the folder you save them to.
3) Once your symbols are saved to dwg or dxf format, open DesignCAD, and use the Batch Convert tool to convert them all to DesignCAD drawings. If you check the box at the bottom of the Batch Convert dialog box to 'Save entities to Layer Zero', you will get the best performance.
4) Now the symbols are in a DesignCAD format and can be accessed via Open or Symbol Load or the Symbol Library command.