Cisco AXL - Determine line with index "1" on all phones

We're playing around with a little web dialler (click to call) for a directory of cisco extensions. I'm trying to determine the ip address of a phone with a line that is a particular pattern. The problem i'm having is that we have users that have their main line appear on others phones. I've tried a number of different ways to get the information I need and a lot of searching..

soap:selectCmDevice returns the lines however they can be out of order, for example:-

<ns1:LinesStatus>
   <ns1:item>
     <ns1:DirectoryNumber>731763000</ns1:DirectoryNumber>
     <ns1:Status>Registered</ns1:Status>
   </ns1:item>
   <ns1:item>
     <ns1:DirectoryNumber>731768766</ns1:DirectoryNumber>
     <ns1:Status>Registered</ns1:Status>
   </ns1:item>

In this example, 731763000 is a shared line that is used by multiple phones on key 2, however it shows up first on some phones. It seems that the only way to get the actual index of the line is by doing a getPhone?

<lines>
  <line uuid="{80B76A68-436E-683E-F0E8-8B6B4859D9BF}">
    <index>1</index>
    <omitted..>
  </line>
  <line uuid="{964FC816-74D0-D660-17DC-C723D9AF73E7}">
    <index>2</index>

That is what i want, but i want to be able to do this in one request, for all phones. listPhone returns all phones, but not any information about the lines.

Is there any way to craft the getPhone soap request to get this info in one go for all phones?