you can't but let's keep in mind that this utility was born in good old times when
posts were smaller and you were lucky enough if you managed to get a single
scene. (Damn, that makes me feel a pr0n vet 'cause I remember those times. Sigh...
)
I agree that the command line mode would be useful, let's hope Murmel has it on
to-do list and will implement it one day. Anyway it's a great proggy, big thanks
to the author! 

(Off topic: I have no idea if anyone uses the command-line version of FSUnmask to extract
my posts but I thought why not to provide it if it can save someone a bit of his/her
valuable time. I haven't got any feedback so far but I hope some people find it useful. Also
I'd like to thank you for finding time to reply to my posts, jonni32 - it's much appreciated
and I hope you really like 'em!
)
Cheers!