I am lt col served in Bangladesh Army for 24 years. I want to join u.n forces as mil observer or in any un job

I served as an Army officer in Bangladesh Army for 24 years I retired as a lt col in 2000 . I was in the Infantry regiment I served both in the field and staff jobs satisfactorily . I have also served in U.N Mission in Iraq Kuwait border for one year . Now looking after a Garment factory in Bangladesh . Can I have a job in the U.N ?