Yes. You can create a stationery file from any script whose format you want to use as a new default template.
When you want to open a new document in this format, go to File > Open and select that stationery file. This will open an untitled document in this format. Any changes you make will not affect the original file.
NOTE: All support for Final Draft AV, including software activation, has been discontinued. You may find solutions to problems in the online knowledge base or in the PDF manual found on the installation CD.