How to create a sequence of filling cells in Excel or Google Docs?

Question

excel

There is an ID column, how to make each of its cells filled when dragged by n + 1, but at the same time having not only numeric values, but also letters.
For example: RT00001DZ .
Well, so that by dragging, for example, all cells are filled with a number 1 more than the previous one. Result: RT00002DZ . Etc.

Answer 1

It is possible through the format. Format code:

"RT"00000"DZ"