Hi Lynn,
The Log object is available when TC is in script running state. You need to use it while the test is running. There's no documented way to export logs if TC is not in the running state, however, the Integration object provides a way to do this. It is an undocumented way which will be suitable in your case.
After the loop which checks the running state, replace the SaveResultsAs call with the following line:
Call TestCompleteObject.Integration.ExportLastResult("{C32B59B0-6AD4-4921-A545-021C7B76E526}", LogFileName)
The first parameter is a GUID which corresponds to the MHT format of exported logs. The value hard-coded in this example will work if you export logs to MHT, and won't allow using other formats.