Integrate data from file

I have a question about integrating data from a text file in COMSOL. I haven't been able to find anything on how to do that, but I think it's pretty simple. The data has two columns, the first being wavelength (nm) and the second being spectral irradiance data in mW/(cm^2 nm) (AM1.5 Spectrum). I want to integrate the spectral irradiance data accross all wavelengths to get power density.

Thanks!