Assign Custom Property to a Variable

I want a custom property "Area" to be assigned to "SW-SurfaceArea" with
a macro
(or automatically to large number of existing files). For new files,
I've added property to template.

The manual way to do this is
go to Custom Properties
Property Name: Area
Type: Text
Value: "" (select from scrolldown)

How do I add Property and value(referencing file) with a macro?

I use the following line and get SW-SurfaceArea for Value.
I need "SW-SurfaceArea" to be evaluated. How do I get the quotes?

retval = Part.AddCustomInfo3("", "AREA",
swCustomInfoText,"SW-SurfaceArea")

Thanks, Blair

BTW: I'd prefer a dynamic link, so I haven't used GetMassProperties

 

You can try my macro if you like:

http://www.rhapsodydesignsolutions.com/programming-1.html

 

Thanks Keith and Steve for the responses.

Keith, Propagator does add "smart" mass properties which was what I
wanted.

Steve, Thanks for sharing your Macros. Batch-Add-Macros add the smart
properties that I want.
It also allowed me to peek inside and see that I had to put together a
string with " in the form of ch(34) to keep the quotes necessary.

Thanks for the useful help.

Sincerely, Blair