With the installable Pipeliner add-on, it is possible to save already created Power Point presentation directly to Pipeliner.
Once the presentation is created, it is enough just to:
1. Click on the Home button
2. Click on the option Save to Pipeliner
3. Select the Entity type (Account/Contact/Lead/Opportunity), select the specific Entity and then Open it
4. Name the presentation (optional) and then click on the Save button
5. Once the presentation is saved, it is enough just to open Pipeliner, enter the Entity where the presentation was saved and in the Documents section you may access it