Encapsulating an SOPC megafunction inside another module

How would one encapsulate an SOPC ready megafunction inside a custom written module? I have a need to design a module that would readily encapsulate two Scatter-Gather DMAs. Is this possible? What would be the steps in the Quartus II and SOPC builder?

I am already writing some custom modules that I can include in an SOPC stream, but just can't seem to figure out how to get an SGDMA embedded inside. I use the BDF editor to generate verilog at the moment.