You can however make SF9 available to directly pass audio from Sonar to SF9 for edit then save and return without having to copy and paste any data.
It installs SF 9 as a tool in the utilities menu. Highlight a piece of audio and just that part is opened in SF9 for editing in way you like using any of SF9s tools and when you're finished the Audi is passed back to Sonar. This is destructive editing.
I'm not at my PC at the moment so can't give you the step by step instructions but I'm sure someone will come along and link you to where the instruct is are locate. It requires a registry edit so as long as you're comfortable doing that, all good.