CAD to Google Earth

i am working on converting CAD file (DWG, DXF) o show on GE

for this i need to convert my design in DAE and then convert it in KMZ…

i have used the Collada DOM conversion code but it cudnt convert DFX->DAE properly i mean it exported the file but there was no DATA inside that file

please help me in this would i have to write own converter? or there is another way?

thank you