I suspect you mean sub domain?
go to clientzone.afrihost.com and log in.
Click on the domain on the right
Click on CPanel
On the next page click log in to cpanel
A new tab will open with your CPanel
Under "domain" Heading click sub domains
in the text box type the name for the sub domain eg. for this site: (.) is there and a dropdown for your domains eg. sub.domain.tld