It won't work. Your hard drives are formatted as MBR. On an MBR system, the boot partition has to be 1st partition on the drive. So even if you did manage to copy the boot details over onto O the PC wouldn't be able to boot off it.
now there are 2 ways to fix this...
download the
Windows 10 media creation tool and use it to make a win 10 installer on USB
1. you can try to create the mbr on C but before you do it, take all other drives out of PC or the process will just use the pre existing one
obviously PC won't boot without the missing partition so use the installer
change boot order so USB is first, hdd second
boot from installer
on screen after languages, choose repair this pc, not install.
choose troubleshoot
choose advanced
choose command prompt
Follow this:
https://www.lifewire.com/how-to-rebuild-the-bcd-in-windows-2624508
2. other way is a fresh install of win 10 but without any other drives attached as then windows will have to make the boot partition on the ssd. Once windows boots from drive without usb, unplug PC, reattach the other hdd(s) and make sure the other drive isn't added to boot order
or just ignore it and fix next time you fresh install, as both drives are ssd (right?) so boot times aren't going to be much faster regardless of where boot partition is.