Configuration UI interface

I recently have a requirement from bussines to create a tool that customizes the data of our applications, for example:

if ("field x1" is "value 1" and "field x2" is "value 2") or ("field x3" is "value 3") ... then set the value of "field y" to "value y"

Now I have a mechanism (BRMS as an engine) and a UI that looks like this:

http://www.telerik.com/help/aspnet-ajax/filter-basics.html

or

http://devexpress.com/Products/NET/Controls/ASP/Grid/filter_editor.xml

but our business says it's hard to use.

Is there any idea about Boolean Expression view and input interface other than these?

I really appreciate your help. Thanks anyway.