SKILL to add instance properties

Is there a SKILL function that can be used to add a property to a layout instance?

I am trying to transfer properties attached to specific instances in one db to a duplicate db that is missing them.

I can locate instances in the source db with the property to be transferred - (something like this except it will ultimately operate on a library):

{

cv=geGetEditCellView()

StPropInstList = setof( inst cv~>instances car(inst~>prop~>name) == "MY PROPERTY")

}

 ...but in my destination db, I cannot find SKILL code to perform the equivalent of  - for each instance, opening the Edit Properties form (leHiEditProp()) and manually adding a new property and defining its name and value.  It seemed that a new property could be assigned using myinst~>prop~>name = "My PROPERTY", but this does not work.