BCX MKDIR will create only one new folder per call, so only the last component of the MKDIR argument is used to create a new folder.
Here is a snippet that uses the Windows system MKDIR command to create several folders at once.
In the example, you may be tempted to move the DQ$ encapsulation to the PathStr$, but I'm sure I heard someone say, "No no !!!"
DIM PathStr$
PathStr$ = "C:\Windows\Temp\BCX\Does\It All"
SHELL "MKDIR " & DQ$ & PathStr$ & DQ$
IF EXIST(PathStr$) = 1 THEN
PRINT "MKDIR has created " & PathStr$
ELSE
PRINT "MKDIR did not create " & PathStr$
END IF
It would be interesting to see a pure BCX code that does this.