Phone [Q] Live boot s4 from sdcard

Am having a Galaxy s4 i9500 with original ROM and it is not rooted. Is it possible to boot cyanogen mod or any other rom from a external sdcard without flashing my device's internal memory? The device's recovery and odin mode are accessible.

Few other details:
1. I've forgot the lock screen password and have not registered any other laptop/computer for usb debugging
2. The purpose of booting from sdcard is to access my device's internal memory and take backup
3. If possible reset the password of my device after live boot (Note: Android device manager is not enabled for remote lock/erase )