Does Zoom Search use the keywords entered on the properties page of a text file?
If you are talking about a real text file full of ASCII text, the answer is no. Only the content of a text document is indexed. Strictly speaking the additional data you can enter in Windows XP is not part of the file and will be lost in general when you move the file to a web server or access the file through a web server.
If you are talking about a Word or PDF document, then the answer is yes. The meta data is indexed.