There was a thread here not too long ago about making balms with essential oils and beeswax pellets but I don't remember who was doing it. I believe @troy had tried mixing balm with either beard or mustache wax to adjust the amount of hold, he might be able to offer some suggestions, hopefully he'll remember the thread I mentioned and be able to point you to it. If you check out the ingredients list of a few beard balm and wax makers you could probably come up with a base recipe and then tweak it to meet your needs. You could order a few beard wax samples, that might be all you need.
Good luck with your idea.
I do sometimes mix waxes and oils or balms and oils, but for the opposite reason. I'm usually looking for less hold. I like to keep mine more natural looking and want it to move a bit with me and fall more or less back in place as I go through the day. My guess would be to add more bees wax for more hold. I don't ix up batches though I just mix a little together in my hands before applying to the beard and stache.
There may be some good info for you in this thread Making my own beard balm/oil and moustache wax?
Good luck and keep us posted on how it works for you!
This thread might be helpful too, the third post (by @AimlessWanderer) describes adding wax for more hold: Scentless Beard Oil
Let us know what you come up with, it might be helpful to other members with the same concerns.