http://www2.sqlblog.com/blogs/davide_mauri/archive/2013/01/30/forcing-custom-properties-of-a-data-flow-transformation-to-support-dts-expression.aspxToday I was using a 3rd Party Data Flow component that has several Custom Properties for which I need to change some of their values at runtime using a DTS Expression. To mimic the situation let’s use the “Percentage Sampling” that has two Custom Properties:enCommunityServer 2.1 SP2 (Build: 61129.1)