Viewing Several Type of Files at the Same Time

In the Open dialog box of any applications, Microsoft Word for example, you can see list of several type of files at the same time. You only need to type all extensions, and use semicolon as the separator. For example, to see the .DOC, .TXT, and .RTF files, just type *.doc; *.txt; *.rtf in the File name column, and then press Enter