JMeter Test automation ($15)

Problem description... I need help in 2'rd point only where I need to write code for counter.. I do have 2 jmx files.. 1. First file , I am doing some work and saving some data in to csv file which i need to use in 2'nd jmx file. 2. In 2'rd Jmx file , I do have 5 thread groups. I want to run first 4 thread groups 3 times after 15 minutes interval and after the third run , i want to run the last thread group where I am actually terminating the account. So, Can you help me writing a small code /or a way where I can run first 4 thread groups 3 times after 15 minutes interval and then run the last thread group.