How do I create geometry features from input attributes?

I see how I can create a geometry using a creator where I can specify the geometry parameters. For example, creating an Clothoid by specifying Start X, Start Y, Direction etc. But these are all values that must be hand entered. How can pass these values into an "inline" Creator to set the geometries accordingly? I see 2DArcReplacer etc but not one for Clothoids. Is there a GeometryReplacer of sorts that would let you specify the type of geometry desired and which incoming attributes to assign to the relevant Geometry Parameters?