I have not been working with DLL projects much in the past and never with 64 bit DLLs, but usually one had to debug the DLL project, set the host application to use in the Run -> Parameters dialog, set a breakpoint in the DLL funtion of interest, and then just run. Do the required actions in the host to end up in the DLL at the breakpoint.
If you end up in the CPU view this means that the debugger cannot find the debug information for the code you stepped into. Make sure you build the DLL with debug information. 64-bit apps are debugged in a kind of remote debugger session since the IDE is a 32 bit process. So make sure you have enabled "include remote debug symbols" in the linker options.