Hyperlinks may contain URLs that when clicked open a browser window and navigate to the specified site (for example, "http://developer.mescius.com"). They may also contain references to files that are launched by the application associated with the file type (for example, "readme.doc"). Finally, hyperlinks can be used to send e-mails (for example, "mailto:joe@foo.com").

Each cell may contain a hyperlink and a value. However, if you assign a hyperlink to a cell that has no value (Value == null), then the hyperlink text is automatically assigned to the cell value as well.

Reference

XLCell Class
XLCell Members