A simpler, more temporary approach would be passing the feed lines through
the open window and closing it gently.  But be careful, because crushing
coaxial cable will give you nothing but trouble.  Be sure to secure the
window with a block of wood or some other locking device, your new equipment
seen through an open window may tempt an unwanted visitor.
Another important requirement for your station is comfort.  The space should
be large enough that you can spread out as needed. Operating from a telephone
booth is no fun.  Because you will probably be spending some time in your
shack, an understatement, be sure it will be warm in the winter and cool in
the summer.  It should also be as dry as possible because very high humidity
can cause such equipment problems as high voltage arcing and switch contact
failure. +