Hello Tman,
This is a slightly tricky question. The reason being, the report options like the report path etc, are set before you see the serial number prompt when you run your UUT. There might be other ways of getting around this, but a quick solution would be modifying the process model.
I modified the PreUUT callback to set the report options. I passed the reportOptions as a parameter to this sequence. In the PreUUT sequence, I set the following fields:
Parameters.ReportOptions.GeneratePath=False
Parameters.ReportOptions.ReportFilePath= "c:\\"+ Locals.SerialNumber +"\\report.xml"
I hope this would give you an idea.
SijinK