Search For File

Hello, I am trying to write a simple application using PHP on a Windows 2000 server. There is one text box for input and one search button. Basically the user would input a file name (for example "help.pdf") and then the php script would search a directory (for example "c:\help\") and subfolders for that file. If the file is found, I would like to automatically display the file using Adobe Acrobat. Ideally I would like to be able to use wildcards and obtain a list of results linking to the files. Any ideas on a good way to do this? I am mainly interested in how the search should work. Thanks Jamie