origional dwg file is in 1:200 but when i insert a block it is to be upscaled to suit the origioal dwg.how do i keep the same dims when interpretation the sizes for new machine space,the inserted scaled up block has the wrong dims[doubled].how do i keep origional sizes

Set the proper scaling in both the source and target drawings - see the tip:http://www.cadforum.cz/cadforum_en/qaID.asp?tip=4581