eCart cannot do a product ID rtange.
You should create a new column in the cart for discountable items. set the value of this column to 1 for items that can recieve the discount and 0 for items that cannot recieve the discount.
When creating the discount rule use the following triggers:
Based on Session Variable Existence:
Is session Variable [<session name>] exists
AND
based on session variable value:
If session Variable [<session name>] has a value [=] to [<xxx>]
AND
number of Products with a specific column value;
If the number of products where [discountable] has a value 0f [1] is [>] a value of [0]
The use the Flat Rate calculation to apply the $10 discount.