In principle this isn't too difficult. In pseudo code you would:
1. Get the path to the folder where your files are.
2. Get the name of the first subtool and concatenate it with the path & extension to form the file name.
3. See if there's a file of this name in the folder.
4. If there is a file, go to the relevant (presumably lowest) subdivision level of the subtool and import the file.
5. Repeat for all subtools.
For (1) you can either hard code the path or use a text file which is read by the zscript.
For (2) you would do something like:
For looping through the subtools you can adapt this macro: http://www.zbrushcentral.com/showthr...l=1#post798045
Let me know if you've any other questions,