How do I request XML through Google Scripts? Idle Gmail Accounts

I am trying to create a Google Apps Script that I can run to determine how many Idle accounts we have that are past 90 days (even 60 days). We need this for our enterprise in order to delete obsolete users accounts and reassign licenses to active/new users. Below is the XML Request but I am not sure how to code into the script let alone run it - any helps/tips are appreciated!

<?xml version="1.0" encoding="UTF-8"?>
<rest xmlns="google:accounts:rest:protocol"
    xmlns:xsi=" http://ift.tt/ra1lAU ">
    <type>Report</type>
    <domain>example.com</domain>
    <date>2014-01-01</date>
    <reportType>daily</reportType>
    <reportName>activity</reportName>
</rest>

date,num_accounts,count_1_day_actives,count_7_day_actives,count_14_day_actives,
    count_30_day_actives,count_30_day_idle,count_60_day_idle,count_90_day_idle

20140101,46,34,38,41,44,2,1,0
20140102,75,61,64,69,73,2,1,0
20140103,78,65,68,73,76,2,1,1
20140104,82,68,72,77,80,2,1,1