It's kind of funny how, every time someone asks a C3D question here, a bunch of people chime in about how you can do it in pretty much any software EXCEPT for C3D...
But in C3D, you have a variety of options. If they are old Softdesk or Land Desktop points, you can convert them using the tools on the Home tab -> Create Ground Data pane -> Points.
There are also tools for "Move text to Elevation" and "Move blocks to Attribute Elevation". You can find those by going to the Modify tab in the Ribbon, select "Surface" in the "Ground Data" pane, then look in the "Surface Tools" pane.
If none of those options work, then you also have other options, such as DATAEXTRACTION and Map Queries.