Hey, Esko; if I understand you correctly, you have out swinging, side-hung 'awning' sashes on the outside; and inside swinging, side-hung awning style sashes on the inside?
Basically what we'd call storm windows on the outside.
You're looking for locking latches, not closers?
Over here, the old windows had a sliding rod running through a pivoting hub, screwed to the window stooll...the sill being the exterior bottom ledge...which acted as a means of locking the window in any position. This would have been in addition to the actual lever latch.