Service Invoice Discounts with Service Contracts

Hi,

Wondering if anyone knows how to automatically calculate the the discount that a customer receives when they are on a service contract plan through the assembly 9-3 screen?

Some background I currently have all my service technicians on Sage Service Operations which is where we commonly send our invoices from, but sometimes we also send the invoice directly from our office using the service invoice report. I would like the discount that these clients receive for being on the plan to show up on both invoice formats. I can edit the form design to make a calculated field to get the discount for the Sage 100 side, but this does not correlate with Sage Service Ops which I would like it to. Both the invoices below show the two formats that we currently used. The Total price actually includes the discount, but it is not shown on the invoice. The nondiscounted price is supposed to be 443.56. Also due to the way that assemblies work the discount given to Contract customers is not shown as an expense on the income statement, but instead the revenue is just shown as a reduced price. i.e. the transaction looks like:

Cash debit 399.20

Service Revenue credit 399.20