If you are developing a MS Office 2010 add-in and want to know what are the possible values for imageMso to add icons to the Ribbon or any other place inside the PowerPoint editor then you can use the following approach.
You can download a macro-enabled Word document that will list all the icons for you. This knowledge was based in the article you can find here. Download this macro-enabled document to see the icons available in MS Office 2010 which is great for software development.
Once you open the document in Word, you need to activate the macro and then look for ImageMso 0 and ImageMso 1 under the Office Backstage.
What is the Office Backstage? Accordingly to this post, the Ribbon contains the set of commands for working in a document, while the Microsoft Office Backstage view is the set of commands you use to do things to a document.
Even if there is no a search icon feature, you can locate the icons by browsing these lists since are ordered alphabetically. If you want to locate an icon for export action, then you can look for the icons starting with E char.