Hey, here i am with another stupid question

I have an array which hold 2 things: a list of the full paths of apart and the quantity of the part.

eg: customprop(0)= "c:\test.sldprt" and customprop(1)="1"

what i want is a macro who does the following:

open the first part in the list
add or change the custom property "quantity" of the part to thevalue from the array
close the first part
open the second part
add or change ....

i've been trying all day now, but i just can't get it to work.could someone plz help me...

tnx a lot guysSolidworksApi macros