You might be able to...
Volume
Number: 7 (coarse) 39 (fine)
Affects:
The device's volume level. If a MultiTimbral device, then each Part has its own volume. In this case, a device's master volume may be controlled by another method such as the Univeral SysEx Master Volume message, or take its volume from one of the Parts, or be controlled by a General Purpose Slider controller.
Value Range:
14-bit coarse/fine resolution. 0x0000 to 0x3FFF where 0 is no volume at all.
NOTE: Most all devices ignore the Fine adjust (#39) for Volume, and just implement Coarse adjust (#7) because 14-bit resolution isn't needed for this. In this case, maximum is 127 and off is 0.
If that is so, then ignore the #39 and use the 7. Now to what point this will be straight forward i dont know.
I do know that several of the previous attempts i heard they always ran into some issues( not sure what) when trying to implement the 7 bits controllers... Now what that was, im not sure... You will have to do it by trial and error, i guess !