Topic: How to have variable in fixture for testing in ActionMailer

I am new to Ruby and for Testing in Ruby too. 

This is my fixture data

one:
  uid:  1
  terms_of_service: 
  shipping_policy: 
  payment_received_email: 
  payment_reminder_email: 
  item_shipped_email: 
  paypal_email:  legan@abciz.com
  preferred_payment_method:  paypal
  preferred_payment_card_visa:  N
  preferred_payment_card_discover:  N
  preferred_payment_card_amex:  N


The fields(email content)

  payment_received_email: 
  payment_reminder_email: 
  item_shipped_email:

are supposed to have some string and some variables together like

"Dear [:buyername], This is a payment remainder for the amount [:amount], ....."

These variables buyername and amount will get assigned when my test script is running from another fixture data.

Can someone help to write the fixture for this situation.

needed help very urgently

Thanks