setting up a CIFS mounted drive as ftp home directory

Hi here is my problem,

I have a server in a public cloud and I have a CIFS folder withe the cloud provider, I use that folder to backups DB. Then I dont have access to this CIFS folder from outside the cloud network, but I need it to. So my idea was to set-up an FTP server at the cloud server in wich I could point the FTP home directory to the mounted CIFS FOLDER(Z:). 

Finally when I try to connect to the FTP it shows "The user cant acces to the home directory folder". the CIFS use user/password 

is posible to do that I want to do?

Thanks