is it possible to send a file to specified ip? which the user of the ip isnt on connecting to my currunt network?

yes

on the recivers mirc there is under options (alt-o) DCC/SERVER it must be enabled, the PORT number must be known (by you), and the listen for sends must be ticked. The recievers PC also must have a clear route for that port to the mirc (obviously else mirc wont hear it)

then u the sender type in
/DCC SEND <ip>:<port number> filename

example
/dcc send 127.0.0.1:59 blah.txt