Hi Jon,
MS Powerpoint does provide an ActiveX object that you can automate using LabVIEW. It's call Microsoft Powerpoint 9.0 Object Library. I'm not familiar with this activex object, so I can't offer more help.
I do have an example that shows how you can launch a powerpoint presentation using LabVIEW. Please see attachment.
If you post your question on the LabVIEW developer exchange you may be able to get more help.
Thanks,
Ken Sun
Applications Engineering
National Instruments