I have been trying multiple formula to get results for Column D as shown below...(column `d`

is normally empty. I tried matching, if, and lookup formulas and have yet been able to successfully complete the task). Column `A`

contains random ID numbers. Column `B`

contains the "parent id numbers. I need a formula for IF column `B`

is greater than zero look in column A for that number... THEN copy from column c that cell value. I have used this but wont copy `c`

value when going down the list `=IF(C3>0,LOOKUP(C3,A2:A20001,D2))`

```
+----------+----------+-----------+----------+
| Column A | Column B | Column C | Column D |
+----------+----------+-----------+----------+
| 279 | 0 | P12345 | |
| 281 | 279 | 69856 | P12345 |
| 282 | 279 | 656898 | P12345 |
| 283 | 0 | 6464845 | |
| 301 | 285 | 12156498 | |
| 322 | 279 | 6588446 | P12345 |
+----------+----------+-----------+----------+
```