At least in DOSBox-X version 2022.09.0
(1), you can mount a sequence of disk images to drive A:
simply by mounting from the drive menu:

You should probably first select the Option: Mount images read-only
option so as not to allow changes to the image files.
If you load a sequence of images, you use Swap disk
to cycle through the drives one by one, then finally Unmount drive
to unmount the entire sequence when you're done.
This can also be done using the CLI tools imgmount
and imgswap
, but I prefer the menu-based method myself. However, should you prefer the CLI tools, you can run them with the /?
flag to describe how to use them. Just keep in mind you're unlikely to be able to run CLI tools if you're in the middle of installing an application in DOS (the installer will be in control rather than command.com
.
(1) This is the version I'm currently running, having not yet upgraded to the latest (at time of answer) 2022.12.26
, That's due to the fact that the Windows installers were not actually built for that release.