[NAME]  You can try it and you won’t damage anything, but I don’t think it will work properly. Those docks are meant to have at least a 130W power source (or even higher when using certain laptops with very high power requirements), so using a power source with half that amount of wattage might not work. Unless maybe you have a laptop that is only designed for a 45W source, in which case you might get lucky. But if your laptop is designed for a 65W source, the problem will be that the dock reserves some power capacity to run its own electronics and power any USB peripherals you might plug into it, which means it doesn’t pass the full capacity through. That’s why docks need to have power supplies with more capacity than just what the system is meant to have.
I have dock station Dell E-Port PRO2X without AC Adapter and laptop Dell Lattitude E5420 with AC Adapter PA-2E 65W 19.5V 3.3A  Can I use adapter from laptop to supply dock station or I need original PA-4E 130W 19.5V 6.7A adapter?  
AC adapter for Dell E-Port PRO2X