In DxDesigner, you can use automation to add parts to the schematic:
comp = block.AddPartInstance(partition, device, symbol, x, y)
Once in the schematic, they are pulled into the design at the next forward annotation, if not already present.
However, if I understand your question, you are trying to pull parts from the Central Library into a PCB design. I don't know of a way to do this
Yes I will pull parts from Central Library into a PCB design (Expedition) using automation command Document.PutComponent.
The 3rd parameter of this command is bFromCentralLib as Boolean but it doesn't work if you set this parameter to true.