Part of my job is developing gel-type soft gelatin capsules. We often suspend powders into oils prior to encapsulation.
The simplest way is to increase the viscosity of the oil by using something like beeswax, hydrogenated vegetable oils, coconut oil, glyceryl monostearate or one of the other options available to you. Melt the chosen ingredients into a small portion of the oil and then whilst hot, mix into the remainder of the oil. Then you can add the powdered/insoluble ingredients into the oil.
Be careful - hemp seed oil is unsaturated and will go rancid very quickly (with or without inclusions). You will need some antioxidant. Also, from experience you are unlikely to get much more than about 10% herb extract into the oil before it becomes and unusable oily dough. This does very much depend on the extract - freeze dried powders tends to be worse and will seize the oil. Aqueous-Ethanolic extracts tend to be better - but there are so many variables that can go wrong. You will most likely need to use lecithin. Lecithin helps to “emulsify” the powder into the oil. It also improved taste too since I suspect you are intending this as an oral product rather than a topical product.
And as @Pharma says, you will very likely have a clogged pipette - no matter how finely you mill the powder