Bind Alphabetic range to DropDown List

I need to bind dropdown with A to Z (Can be vary) values.

We can bind dropdown with numeric values like below,

int start = 0;

int count = 10

ddlNumeric.DataSource= Enumerable.Range(start, count);

Similarly looking for Alphabets where parameters can be configured.

Scenario #1 :

Start = A

End = Z

ddlAlpha.DataSource = Should display values from A to Z

Scenario #2:

Start = F

End = N

ddlAlpha.DataSource= Should display values from F to N

Start & end range should be configurable.

Appreciate

Thanks