How to use a prefix in e-mails?

Hi,

The current e-mails that are sent when a customer orders begin with this:

"Hi, name,

blablabla"


What I want is make this a little nicer and check if the customer is male/female (address_title field).

"Hi Mr. name,

blablabla"


or

"Hi Ms. name,

blablabla"


I use the address_title field, so how can I query this field in the e-mails and replace the result with 'Mr.' or 'Ms.' strings?

Thank you,
Maurice