I use StartLogic Hosting and I found that creating a CNAME wasn't as simple as what I read in the support overview. So I contacted StartLogic for some help and this is what they told me. Hope this may be of help to others.
Creating a CNAME using StartLogic hosting:
You can create a subdomain, cms.mysite.com, and point it to cms.pagelime.com using the Custom DNS Record tool found under the Domain tab. To do so, please follow the steps given below:
1. Log into the control panel (vDeck) with your account username and password.
2. Click on ‘Custom DNS Record’.
3. Select the domain name you will be using (ex. 'mysite.com') and click on ‘Go’.
4. Under the ‘Points To IP’ textbox, enter the IP address mentioned near/below that textbox.
5. Under the ‘Subdomains’ section, enter the subdomain name or CNAME 'cms' (without the quote marks) and in the 'Points to' textbox, enter cms.pagelime.com .
6. Under the ‘Wildcards’ section, enter the IP address which you have entered in the ‘Points To IP’ textbox in step 4.
7. In the ‘Mail’ section, enter the MX record as mx-mg.startlogic.com and priority as 10.
8. Click on the ‘Save Zone File’ button.
The changes will take 1 to 12 hours to update. If you have any further questions, please contact StartLogic via the Support Console.
After you've done all that, don't forget to go into your cms.pagelime.com "account settings" page to add your new CNAME (ex. 'cms.mysite.com') and save. Your new cms site should be up and running and connecting to pagelime without a hitch.