Yammer REST api json. My code send message in group succesfull. But I need to send msg with "cc", link some user, like this:

function yamPostRequest(val) {
var msg_value = document.getElementById('msg_body').value;
var groupID = document.getElementById('group_id').value;
if (msg_value == "") {
alert("Message body cannot be empty!");
return false;
}
if (groupID == "") {
var conf = confirm("Group ID is empty, message will be posted to All Company");
if (conf == false) {
return false;
}
}
yam.platform.request({
url: "https://api.yammer.com/api/v1/messages.json",
method: "POST",
data: {
"body": msg_value,
//"title" : msg_title,
"group_id": groupID,
},
success: function(msg) {
alert("Post was Successful!");
},
error: function(msg) {
alert("Post was Unsuccessful");
}
})
}