When adding a Powerpoint document to a page which contains hyperlinks, you should be able to click those hyperlinks to navigate to the location defined by the hyperlink. Currently, hyperlinks are just normal text.

Notes after additional testing (Steve Shaw):

Confluence Version	Operating System	Browser	Links Worked?
5.10.8	Windows VM	IE11	No
6.1.3	Windows VM	IE11	No  Note, received the following mixed results: Some text that was supposed to be linked rendered unlinked. Some text that was supposed to be linked rendered unlinked but with some preceding text linked. Some text that was supposed to be linked rendered as linked.
6.4.1	Mac	Chrome	No
6.6.0	Mac	Chrome	No
6.7.1	Mac	Chrome	No
6.7.2	Mac	Chrome	Yes
6.7.2	Windows VM	IE11	Yes  Note, this was tested with a newly created page containing test PowerPoint attachments.  Also, this was again tested after upgrading a 5.10.8 instance (that contained a page with PowerPoint attachments that did not render) to version 6.7.2.  When viewing the same page and attachments after the upgrade, the links rendered fine.
6.8.1	Mac	Chrome	Yes

Suggested Workaround: 

Upgrade to 6.7.2