DAQmx does support C++. You can find the function calls in the DAQmx C Reference Help. You can access this file from the start menu.
Start --> All Programs --> National Instruments --> NI DAQ --> NI-DAQmx C Reference Help
Index for DAQmx, and you will see a list of the function calls to the DAQmx driver. If you do not have this file, you will probably want repair the NI-DAQmx driver installation and tell it to install help for C++ when it installs. This will only need to be done if you didn't have C++ installed when you installed DAQmx. Happy hunting!