Writing output files in different directory on fortran

I have this code, but trying to put output files in another directory. how do I solve this? "

  open(12,file='dt.ct',status='unknown')
  open(14,file='event.dat',status='unknown')
  open(15,file='event.sel',status='unknown')

...

  write(*,'(/,a)')'Output files: dt.ct; event.dat; '//
 & 'event.sel; ph2dt.log'

"