Calculating a convolution using conv vs. a loop

Hi,

I'm currently calculating the convolution of a Gaussian and a power law using the following code snippet:

for j=1:1:size(Axis_Tw,1)
    t = Axis_Tw(j);
    if Axis_Tw(j) <= 100 
        temp = 0;
        CPara = 0;
        for i=1:1:nt+1
        CPara = CPara + Gas(temp,Gparams)*PowerLaw(t-temp,Eparams)*dt;

          temp = temp + dt;
          end
          FPara(j) = CPara;

      else
          FPara(j) = PowerLaw(t,Eparams);
      end
  end

I'm trying to use conv to do this instead of a loop. I'm confused on how to do this. Can conv take functions as arguments or can I only use vectors? I've tried evaluating Gas and PowerLaw for Axis_Tw and then passing those arrays into conv, but the result is very different (as in several hundred orders of magnitude).

Thanks, Charles