Well.. I'll save you the trouble. It won't work the way you want it to
The DICE can only control whats native to the unit. The 3.5mm is only and will always only be for audio. period. Now if you want to pair your BT to the china unit no problem but you will not be able to advance tracks or see song info because again, the 3.5mm jack is strictly for audio. You basically have a very expensive factory AUX jack with iPod integration for devices of yesteryear.
Your only maybe viable option is using a 30 pin to BT adapter like this one...
https://www.amazon.com/Bovee-Wireles...6315417&sr=8-1
again.. im not a fan of adapter on adapters on adapters but it might be your only choice if you want to continue to use the DICE adapter
cheers.