Mapping for amount based on account

current setup is to receive amount in different columns. "Amount1" and "Amount2"

If accounts are between 1000 and 2000 then Amount to be mapped as (Amount1 value divided by 100 + Amount2 value divided by 100)

else

Amount to be mapped as (Amount1 value divided by 100)

Here is the source file

Account Entity Amount1 Amount2

1000 X 100 2000

3562 Y 200 3000

2000 Z 300 4000

Import Format

Account - Account

Entity - Entity

Amount1 - Amount

Thanks,