Integration limits need to be a variable to integrated value

Hi. How can I tackle this? I have two functions, ALPHAPRODUCT, BETAPRODUCT that need among other inputs D(diameter) to calculate me wave coefficients A and B.

These coefficients I need to calculate monostatic radar cross-section of perfectly inducing sphere, and then, I need to integrate all of that from Dmin to Dmax, and apply some further calculations to get Mie Approximation for Marshall Palmer Drop Size Distribution. The big question is. I need D to vary only due to the integration, so practically everything needs to use it according to that variation.

I thought of making it either as a function handle or as a symbolic value. If I use it as a function handle I get the error "Undefined function or method 'times' for input arguments of type 'function_handle' " or if I use it as a symbolic input, I get the error Undefined function 'besselh' for input arguments of type 'sym'. My code is massive so I can't really copy any because I use a ton of subfunctions, but if somebody has insight, I'd be grateful