how to transfer backup from pc to icloud

Is there a way to transfer iphone backups from a PC to iCloud?

The reason for my inquiry is to try to solve issue incompatibility issue between iPhone 6s and my PC operating on Vista with iTunes. Currently I am unable to restore a backup (from my broken iphone 5c) from my PC to new iPhone 6s.

I was hoping to solve this issue by transferring the PC based backup of my iphone 5c information to the cloud and then restore the new iphone 6s from the cloud.