[xwiki-users] How does one specify regular expression syntax in a Lucene search query

Hi. After much searching around the XWiki documentation, Apache Lucene documentation and googling, I have not succeeded in finding a solution to the following questions: 1. How does one locate all attachments with an extension say 'xls'? I am thinking that the query should look like "filename: *.xls", but Lucene query syntax does not allow * to be the first character of a search 2. Many times users remember some portion of the attachment filename. What would be the syntax to locate such attachments. Something like "filename: *Report*.doc" 3. The SearchApplicationLuceneSearchQueryHelp page on code.xwiki.org does not mention how to constrain a search to a given space. What is the field name for specifying a space. For example trying to locate the homepage of users with first name John by using "space:XWiki name:John*" does not work 4. Going one step further, is there a way to specify a regular expression syntax for a Lucene search query? The range operator syntax is not quite self-explanatory. For a query like "name:[Aida TO Carmen]", what does it mean to locate all pages whose name are between Aida and Carmen? Would it match AidaSummerVacation? I tried "filename:[A TO Z]*.xls" to locate an attachment name 'Test.xls' but that didn't work. If anyone can shed light on educating the finer details of using the full power of Lucene search, I would very much appreciate that. Thanks, Milind