According to this post a few years ago http://stackoverflow.com/questions/3372394/is-it-possible-to-automate-a-click-to-run-application, Office installed via click-to-run does not support ole automation.
Now a few years have passed, I wonder if Office 2016/Office 365 installed via click-to-run now supports OLE-Automation.
One of our software failed with click-to-run installed office. Process Monitor suggest that it is looking for HKCR\Typelib\{2DF8D04C-5BFA-101B-BDE5-00AA0044DE52}\2.8\0\win32 in the registry and failed to find mso.dll. Office itself found in registry HKLM\SOFTWARE\Microsoft\Office\ClickToRun\REGISTRY\MACHINE\SOFTWARE\Classes\TypeLib\{2DF8D04C-5BFA-101B-BDE5-00AA0044DE52}\2.8\0\win32\(Default). Maybe a traditional OLE automation client does not know the new location?