I'm looking for a function which will do the following:

(1) Check each cell in "Sheet1", column "J" for a value of 8, 10, or 12.5

Example: If cell "J5" on "Sheet1" = 8, then add the value of "Sheet1" cell
"I5" to "Sheet2" cell "B17", etc.

(2) If the value is 8, then add the value of the neighboring cell in column
"I" to cell "B17" in "Sheet 2"
(3) If the value is 10, then add the value of the neighboring cell in column
"I" to cell "B18" in "Sheet 2"
(4) If the value is 12.5, then add the value of the neighboring cell in
column "I" to cell "B19" in "Sheet 2"

Any help appreciated.