RusselB's is correct but leaves you open to abuse you would be allowing open read access to your system (well almost open)
I suggest lines like these
on *:text:!send hi.jpg:*:{ dcc send -c $nick hi.jpg )
on *:text:!send blah.exe:*:{ dcc send -c $nick "c:\folder name\blah.exe" }
;etc etc you can even do....
on *:text:!send picture:*:{ dcc send -c $nick "c:\folder name\mypicture.jpg" }
;where your trigger need not be the same as the file you send
This well limit what files you allow and what trigger you allow them on
