Hierarchical Sorting Problem

I have the need to sort the output of a set of process steps into their sequential order. The problem is, the process are numbered according to their place in a hierarchy. For example, I may have a "Process 6.0 Manage Inventory" that contains level 1 processes
6.1 Receive Inventory
6.2 Ship Inventory
6.3 Adjust Inventory

Then within 6.1 Receive Inventory, the following sub-processes:
6.1.1 Receive Advanced Shipment Notification
6.1.2 Schedule Receipt
6.1.3 Initiate Receipt
...
6.1.10 Finalize Receipt

Since these are no longer "numbers" once you add the second decimal point, they won't sort like numbers. My thought is to add a leading 0 to each nested level, but that is proving to be quite the challenge, and I'd rather not clutter up the numbering with embedding those into my process flow diagrams (the origination is Visio).

Has anybody run into / solved this problem? I'd be okay with creating a "sort" field that basically restructures the number with leading zeroes to ensure the sort is correct -- that is,

6.1.1 becomes 06.01.01, 6.1.2 --> 06.01.02, etc...

Thanks!

Rob

This is perfect! Exactly what I needed. Thanks so much for the ultra-fast reply!

Ok -- now I'm feeling stupid. I've successfully used UDF's before, but this function is continually returning the dreaded #NAME? error. Best I can tell, I embedded the VBA in the correct location in the spreadsheet, and I'm getting no errors -- but nothing I do seems to be able to overcome this error. Using Mac 2011 (but have tried on Windows 2010 as well) -- same problem.

I'm sure this is an easy fix...but I'm stumped. Sorry to be so obtuse, but any additional help would be tremendously appreciated.