To patch or not to patch

Hello Everyone,

I just started developing with Drupal last week and I'm on a project where I need to set up heirarchical taxonomy terms in this level (root to base) Country, State/Providince, City (if that tree doesn't exist) whenever a user adds a new special node that we call practitioners to the system.

Now I would like to just plug this into the location.module in the _location_save() helper function and have it call my own helper function within the location.module. That function would basically call some taxonomy functions to do some checking and updating if needed. There might be a better or cleaner way to do this without patching. My boss says he really doesn't like messing with the modules and would rather me create my own module. I told him that I believe that this is probably the most efficient way to do it, but we decided that it would be best to ask all of you.

So should I patch the module or do something else? And if I should do something else, please give me some pointers so I can dig into it and solve this problem as quickly as possible.

btw - This is just goinging into a single site and I don't plan on others using this code, unless you have an interest in it, then I'll post it, but its pretty basic.

Thanks,
Tyler Wright
Creative Fuel Design