Setting Path of Oracle so Dump file can be created on any location

Hi I am using 11G database, Right now for creating Dump file I have to go to Database bin folder(H:\app\Dell\product\11.2.0\dbhome_1\BIN)  and through command prompt I have to go to that path then i am able to create expdp command  but it generated dump file on different location((H:\app\Dell\admin\Raxa7\dpdump) ) what I want is without going to go into Bin folder I should be able to execute expdp command and create dump on same path from any location. Please help how I can do that. FYI I have installed 2 database in my machine.