Can I add a Contact category to the To box when sending email

Can I add a Contact category to the To box when sending email

Can I add a Contact category to the "To" box when sending email. There seems to be no way of doing this. I can open the category in the contact list and select mail to open a new mail with the contacts but cannot simply add a category or see who is in the category to a To or CC box to an email I am already composing.
Am I missing something.
Rob