How to user custom label with phone of contact

I want to add new phone number to one contact with custom label. Is It able to make custom label on Titanium? I can make phone number with precomposed tags, like "home, work, other, mobile, pager, workFax, homeFax, main, iPhone"

I want to use that like below

targetPerson.setPhone(["customTag":['1111-2222-3333']]);
Ti.Contacts.save():