Can I use Global Mapper to cut cross sections with elevation data for a HEC-RAS project?

I was told at the HEC-RAS course that cross sections for a river on a HEC-RAS project can be cut in Global Mapper, and that the cross sections would have LiDAR/elevation data. Is this true and if so, how would this process work? Do you upload your HEC-RAS project to Global Mapper, cut the cross sections in Global Mapper, then import that file back to HEC-RAS? More details on this would be very helpful. (And which version of the Global Mapper software would I need to get this function?)

Thanks