Thanks ejsolutions
I couldn't work out hoe CNAMES can redirect. My DNS knowledge is limited.
I've added the domain to CNAMES but I didn't get the result I was expecting. So I placed a redirect in htdocs.... is that still acceptable?
A www (now considered antiquated) redirect is perfectly acceptable.
You should already have had an CNAME record at your Registrar for www though it's not compulsory, likewise at your server/nameserver DNS. It is these that should've been replaced by A records but you have now circumvented the issue.
(Strictly speaking, having a subdomain as an A record saves one DNS record lookup, over a CNAME but in reality no-one is likely to notice, except when a nameserver is slow to respond.)