On sheet 1 Ihave a list of numbers in column c.

On sheet 2 in column a will be numbers that correspond to sheet 1 column c.
Then sheet 2 column D will have a number hard keyed.

I need a formula on sheet 1 column I that finds the corresponding number on
Sheet 2 and adds up the numbers in column D.

sheet 1 Column c row 1 has 40
Sheet 1 Column c row 20 has 15

Sheet 2 Column a row 1 has 40 and column D has 10
Sheet 2 Column a row 2 has 15 and column D has 3
Sheet 2 Column a row 3 has 40 and Column D has 5

On sheet 1 Column I row 1 should read 15
On sheet 1 Column I row 20 should read 3