Report Control - Commissions for Indivual Sales People

I have written a new commission report that identifies $ Revenue, $ Cost $ Gross Margin & % Gross Margin by Invoice; then totalled by Sales Person. We pay commission as a % of Gross Margin.

We are trying to resolve the following

1. We want to provide an individual report for each sales person, without the ability to customise and thereby gain access to other sales people results.

2. Credit memos are not showing up as a negative $ margin and thereby creates an incorrect figure for commission calculation.

I would like to provide a report for each sales rep for them to view it at any time. I've created the report and used the filter to select the sales report is there a way to save the report so only the administrator or the person who created the report can customise it.