Copy custom properties in a part document

i just created my part template with all the customproperties i want so that when i load it in a drawing verything inmy title blocked is linked to the part.

is there anyway i copy these custom properties to my old partswhich do not have these properties?

it is really very time consuming to repeat all the properties toevery part i have done before.

hope someone can give some ideas/tips how i can do this.

TIA.

-JanSolidworksParts And Features