The code that makes the wheel work on the iPods doesn't work to make actually scrolling on the H10 scroll bar work, unfortunately. I can recall there had been some effort made to figure it out back when the target was still fairly new (in terms of being a Rockbox target, not in terms of recently entered the market) but lately I think that's been dropped. There were (possibly are) some patches on the Tracker of some people's attempts to get scrolling to work but I recall trying them out and they didn't end up working properly.
It looks like the patches are still there:
http://tinyurl.com/yem5omb <-- Tracker search for H10 scrollbar, used TinyURL because all the square brackets in the actual link broke it here on the forum...
You're free to give those a try if you're willing to set up a build environment and compile a customized build with any of those patches included, though I'd recommend only trying one patch at a time, and making sure to revert the patch if it doesn't work or you don't like it. You may also decide to take a look at the code yourself and see if you can't figure it out (assuming you have any coding experience at all).
Also, ignore the first result since it doesn't actually apply to the H10 (I don't know why it even showed up, heh).