Metadata and Tiffs, together with Python?

I'm trying to figure out how to input metadata into a tiff file, and my general web searches are just confusing me. Is there anyone that can point me in the right direction? I'm essentially trying to pull data from an excel file and use that as the metadata for tiffs, but need to do over ten thousand tiff files, and all the data that I need is in an excel file.

python

The Python Imaging Library has tiff routines. Before beating your head against the wall, see if you can use it. If not, post back with an example or two of what you want to put into the metadata. Image formats have become very optionated.

OK... Been playing with the PIL, and I can't seem to get it working how I want it to. I'm still pretty new to all of this really, so it's possible that I'm getting in over my head, but then I learn pretty quick. What we have here is scanned images of geological drawings. I want to embed metadata into them so that they can be sorted through various python scripts, looked up, things like that. I want this sort of information to be input into them in case our organization ever gets messed up, we've got some way to quickly put it all back in order. Also, it will be data that is with the file even if people decide to mess with the file name, or where it lies. Examples of data that I would need in it: Easting1, Easting2, Northing1, Northing2, Elevation1, Elevation2, Filename, Drawingtype, Mine, Scale. Any numbers would work for them, and I've got them all in an excel spreadsheet, if I can just figure out how to input the metadata into the files, I can work it from there. Also, if I'm completely off base with the use of metadata, that would also be something for me to know.

As a more specific example, I need Metadata for the file: "*** - Sections 3840-6615 - Section 4755"

The Values would be:
Easting1: 4755
Easting2: 4755
Northing1: 5750
Northing2: 6500
Elevation1: 15000
Elevation2: 13150
Filename: *** - Sections 3840-6615 - Section 4755
Drawingtype: Cross Section
Mine: ***
Scale: 1"=30'

(The ***'s are just for security's sake... the company is kinda tight on security)

There might be more data too... but if I can find out how to enter it, I can do everything else from there.