It is not possible without a plug in. You can use containers to copy and rename files, but FileMaker does not have the built in ability to create or rename folders.
Couldnt you do it with a convoluted call of a batch job that uses an input file for variable names.
I know that I can execute a batch job with the Send Event  script step.
Windows based though don't know about doing similar on an Apple.
Good idea. Send Event, can be used to launch a batch script, but I'm not sure how to pass a computed value to it to be used as a folder name. If someone can figure that out, this should be possible.
export a single field table as a text file that would comprise the variables.
A quick google search found this which should work for reading the variables in from a text file.
Apple can do it using applescript. I am no expert on applescript but did find example scripts on here to create folders that I was able to copy/paste/modify to do what I needed. I haven't found a way to do it on PCs without a plug-in yet though.