Hola
modifica el caracter del comodín. En vez de * , pon
%
"select nombre from clientes where nombre like '%pepe%'"
Más info sobre comodines:
Cita: The * wildcard should only be used through Access SQL View interface or through Data Access Objects. The % wildcard should be used in its place if you are using Jet OLE DB or ADO.
http://www.devguru.com/technologies/...kref/like.html