Use of user defined functions in double definite integrals as limits of integration

I am trying to create a general function (function to determine centroid of a curve) that I can then use throughout my calculation sheet. I therefore need to pass a function for a curve into my general function, which will be used in a limit of integration placeholder.

I have attached an example. I am able to place my function directly into the integral placeholder to act as an integration limit, but I cannot pass the function into the placeholder via my general function. Is it possible to do this in MathCAD?