A C++ Question; Is it possible to have a polymorphic function that returns various types, dependent on the derived object type?

I am trying to write some code to cache a database table.  The table could have columns containing various basic SQL types, ie int, double, float, string etc.

I was hoping to create a 'cell' object for the table, similar to a spreadsheet cell, that would hold the data.  

To be able to hold the cell in an stl container such as map, I need a common base pointer, so I start with an interface class that has the cell's column name, and some abstract functions that the derived type-specific cells will implement.

How can I create a derived cell type, ie IntCell, that has a 'get' type function to return the cells held int value, but which can be called via the base pointer?  I need IntCells to return ints, DoubleCells to return double values, etc.

I can't have a get function, pure virtual, in the base class, because the return type will be different for each derived cell class.

I could use a template to derive the cell types, but then how would I call the get function via the base pointer?

In short, I need a class hierarchy that allows me to group and access types from an stl container, and that has a get function that returns the contained type.

I have a work around, to use text as the internal storage type, and have various conversion functions to produce types, but I have been tying myself in knots trying to work out a more efficient way to do this.  

Thanks in advance for any help you can give me.