"Route" USB to Android phone through computer Is there any way to plug a USB drive (specifically a micro-sdCard to USB adapter) into my computer, plug my phone into the computer (also through USB), and make it appear to the phone as though I have connected the USB directly into my phone? If that is possible, how can I do it?

If you need anything more, just ask.
Thanks in advance!
Instead of connecting both to computer try using a USB OTG cable.

Because if you connect your phone to computer via USB the computer thinks that you connected a storage and mounts it as a storage drive and same goes with the USB drive (or SD-Card) too. But what you are asking is to mount the USB drive on the phone which is not simply possible unless you are a software specialist with expertise in network and drive handling capabilities.

So, there is no simple way for a USB Drive to show up on a mobile phone connected to the same computer. And I suggest you to use a OTG cable instead if you have a compatible device.