This node takes an integer as input.

Returns the “alphabetical equivalent character”,  and a list from A to the alphabetical equivalent character.

It only works from 1 to 26 (A to Z). [See NumberToCharacter AAZZ for higher inputs]

After this, returns a “Out of range” message.

The node uses DesignScript to work:

There is a local variable, “a”, which is an alphabetical list.

The input, named index in the code block,  is evaluated to see if it’s less or equal than “a” count:

index<=List.Count(a). This is passed into a formula node as the “Test input”.

If it’s true, then, it retrieves the index, less one, in the alphabet’s list. We subtract one unit because we want to make our input “one based”, instead of “zero based”. 1 will equal to A.

If it’s false, the string “Out of range” is passed to the output node.

For the second output, a new list called “b” is defined. Starting with “a” list, it is “choped” in two lists, been the input the chopping point.

The last step is getting the first list, so a” b[0]” is used and passed to the second output. This second output is also connected to te “Out of Range” string if the condition is not true.