Getting a custom field to appear in the query results

Getting a custom field to appear in the query results

Hi,

We have a custom field that is populated when a person is put in as a lead and is then approved to become a contact.

to show this person on a web page, I'm using the api to pull out their details based on their email address

$param = "authtoken=".$token."&scope=crmapi&selectColumns=Contacts(Contact Owner,Lead Source,First Name,Last Name,Account Name)&searchColumn=email&searchValue=".$email."&version=2";

How do i add into the parameters the ability to pull out the data held in a custom field.

Looking at the Contact record for this particular field the id is:  property(CONTACTCF11)

Do I add this into the query so it becomes

Contacts(Contact Owner,Lead Source,First Name,Last Name,Account Name,property(CONTACTCF11)

or 

Contacts(Contact Owner,Lead Source,First Name,Last Name,Account Name,CONTACTCF11)

or do I need to show it as another format?

Any help would be appreciated

Thank you

Darren