Support for Links is limited in PocketPC Help. The only links that are allowed are topic links. You can create these links as you normally do, i.e. highlight some text and right-click and create your link.
Non Topic Links are removed
When you compile, only Topic links will be used. All other link types, including Internet and Popup links will be removed.
In HtmlHelp your image can act as a hyperlink and you can have hotspots within defined areas of your image that link to other topics. In PocketPC Help none of these will work and will be disabled during compile.