Knowledgebase article # 43053 on our website www.na.sage.com provides all of the methods for deductions available for Payroll in Sage 100. There is not one to use the greater of a percentage or fixed amount. You can set the ded goal amount in the Employee Maintenance Deduction task but you would need to manually calculate so you could enter the greater amount of the two. I know for garnishments there are calculations such as this. I am sure some of our Master Developers offer an add-on module for this. Contact your Sage Partner to get you in contact with them.

When Payroll 2.0 comes out next year, I suspect you will be able to do that with a user-defined script (assuming that feature didn't get built in).