Compute for the nth item from the code range of 000A to ZZZZ

How to compute for the nth item from a range of code? The code 000A can go up to ZZZZ. The rule of the 4 characters is that is starts from 0 then the next values would be from A to Z except for the last character since it starts with A instead of zero (000A).

---

Eg.

1st: 000A

2nd: 000B

…

27th: 00AA

28th: 00AB

…

475,254th: ZZZZ

---

475,254 was identified to be the last through this computation since there are 26 letters in the alphabet:

(26 ^ 4) + (26 ^ 3) + (26 ^ 2) + (26 ^ 1) = 475,254

---

How can I compute for the 450,700th for example? Thank you~