How to get the field values from a related custom entity in an email template – Microsoft Dynamics CRM

Hello friends,

I'm creating email template and accessing data fields from custom entity by using this syntax : {!EntityLogicalName:FieldLogicalName;}

and related custom entity (lookup field ) syntax : 

Customer: {!dot_document:dot_Customer/@name;Aaka Restaurant}

Its working great.But my requirement is i need to access Field from lookup entity ,Example :

Document entity :Customer (lookup field) ..I want to access First name,city,or purchase Date of Customer.

I would like to know the way of doing this.I will appreciate if somebody help me.

Thanks,

Piny.