Error "Undefined reference:ds_register".

I am trying to use data server in my application. Basically i have a cgi web server in c using the data server to update some variable. The c program runs fine but, when trying to use data server in a C++ program, i can not even compile.My C++ program is written on QNX Momentics IDE. I keep on getting the error “Undefined reference:ds_register()”

Need help on this, please!