DefaultWebOptions.UseLongFileNames Property (Excel)
True if long file names are used when you save the document as a Web page. False if long file names are not used and the DOS file name format (8.3) is used. The default value is True. Read/write Boolean.
expression A variable that represents a DefaultWebOptions object.
If you don't use long file names and your document has supporting files, Microsoft Excel automatically organizes those files in a separate folder. Otherwise, use the OrganizeInFolder property to determine whether supporting files are organized in a separate folder.
This example disallows the use of long file names as the global default for the application.
Application.DefaultWebOptions.UseLongFileNames = False