Unless you're adding footnotes for each abbreviation, how are you adding the definitions? To use any form of macro-based process, you'd need to have a table of abbreviations and their definitions, so that the macro could look for the abbreviations and add their definitions. Also, if they're going into individual footnotes, be aware that you can't really have multiple footnotes on one line like your example contemplates.

Frankly, a glossary at the end of the document would probably be the best way to go. After all, that's what the table of abbreviations and their definitions to be used by the macro is. It also avoids the risk of having the same definition appearing multiple times on the same page.