You can implement your own types of cells by creating a subclass that inherits an existing cell type (that is, overriding each method in that class). The custom cell type class should be marked as serializable if the clipboard will be used with it or if the export to Excel methods are used.
The custom editor example in the Spread Demo sample (samples folder) shows how to use a control as a cell editor. The FarOut! sample in the samples folder demonstrates custom cell types.
For information on other features of cell types, refer to Understanding Additional Features of Cell Types.