alphanumeric values in Select-Options

Hi ABAP gurus,

There is a select-options for a report like

data : opt1(4) type c.

select-options : g_count for opt1.

g_count would take alphanumeric values like for example

A123 to AB46 . Now it is required to take all the values range

from A123 to AB46 in an internal table .

How do i solvthis .

thanks

ABAP Developer1