Hi,
yes, it can do that. The Prompt Repository is the best place for the recordings, but if it cannot be used, UCCX can deal with recordings coming from a Samba share or even a database.
Take a look at the following documents:
https://supportforums.cisco.com/document/96366/uccx-8x-how-playwrite-file-prompts-fromto-windows-shares
https://supportforums.cisco.com/document/114891/save-recording-database
https://supportforums.cisco.com/document/140786/uccx-readwrite-fromto-sftpftp
https://supportforums.cisco.com/document/140286/uccx-send-recording-or-any-document-over-http-safely-using-base64-encoding
G.