Hi,
in order to copy the contacts under windows from Exchange contacts to iCloud contact, you may proceed as follows:
1- to have a running version of outlook with your exchange account already set up
2- install iCloud for Windows: Download iCloud for Windows - Apple Support
3- configure your iCloud/itune account in iCloud for windows
4- run outlook, and verify both contacts are under my contact tab
5- select exchange contacts, select all (ctrl+a)
6- copy the selected contacts (ctrl+c)
7- go to iCloud contacts
8- paste the copied contacts (ctrl+v)
9- done
since I'm describing the high procedure, this is intended for users with a good level of understanding of windows and outlook, who can take the right actions based on the steps provided.
!!! I did not use google on purpose, since I don't trust google with my professional and private contacts !!!
If you have any suggestion to improve the procedure, please feel free to revert back with your comments and suggestions.
good luck.