Excel supports a limited wildcard capability -- search Excel help for the keyword 'wildcard' (without the quotes).
VBA supports a significantly better capability through its LIKE operator -- search Excel VBA help for the keyword 'wildcard' (without the quotes).
However, now that VBScript supports regular expression, it is possible to dramatically enhance the search and replace capability of both VBA and Excel. The following are two wrapper functions that allow the use of regular expressions in Excel formulas!
For more examples see my posts here (also search for regexp and author tusharm), as well as the Google archive of the Excel newsgroups. There is also a lot of material on the web. Search Google for more.