As per the title how can I find the
image location of an image inserted in to a Word 2003 document?
Maybe not for Word 2003 but if it is a matter of finding the source to which an image is linked then the following might work:
Right click on the image (may require two clicks). A menu should pop up including something like Linked Photo Editor Photo Object click on that, click on Links and where Source file: should show the file name and full path.