best way to index numerical data ?

[Jack]

Hi I have a lot of data that is in a TEXT file which are numbers does
anyone have a good suggestion for indexing TEXT numbers (zip codes,
other codes, dollar amounts, quantities, etc). since Lucene and other
indexers are really optimized for Alpha character indexing. What
approaches are typically taken in computer science for example to index
text numbers..hash maps or something else ??

Thanks,

Jack