building data file by vmd or other software

hello dear
i want to simulate water and nano fluid cu in a fcc lattice...water is base fluid and cu is a region (sphere or box)in the center of lattice (between water)
does anybody have any tutoral or receipy to build it by related software (sprcially vmd).....water molecules are in the range of 1000 to 1500 and cu atoms are about 400 to 500...