find and replace - based on 3 character in adjacent cell

Hello everyone!

I would like to replace CODE to Product Name based on criteria in INVOICE NO.
The criteria is:
1. If INVOICE NO begin with "A", it will identify the 3rd, 4th & 5th character and
match with the product name. Then, replace code to product name in the right cell.
2. If INVOICE NO not begin with "A", it will identify the 2nd, 3rd & 4th character and
match with the product name. Then, replace code to product name in the right cell.

For example:

x101xxxxx - Apple (Change/insert 20805002 to Apple)
Ax101xxxxx - Apple (Change/insert 20805002 to Apple)

x102xxxxx - Orange (Change/insert 20805002 to Orange)

x409xxxxx - Grape (Change/insert 20005008 to Grape)
Ax409xxxxx - Grape (Change/insert 20005008 to Grape)

See attachment for better understanding.
Your help are highly appreciate!
Thanks!