Help Needed - Update Property Automatic Value Without Resetting Every Time

Dear Community,

I am trying to achieve something, and I need help with (possibly with scripting).

I have a property (Prop. C), whose value I want to increase by the value specified in another property (Prop. A) each time a new object is created. However, I want Prop. C to retain its current value each time it is incremented by Prop. A (similar to how Simple Automatic Numbering works, however, in this case, the increasing value is always specified in Prop. A, as shown below:

I have the code below, but Prop. C resets to zero every time a new object is created (instead of increasing the last value)

Dim PropValue
Set PropValue = vault.ObjectPropertyOperations.GetProperties(ObjVer)
Dim Prop_A
Dim Prop_C
Prop_A = PropValue.SearchForProperty(ID01).Value
Prop_C = PropValue.SearchForProperty(ID02).Value
Prop_C = Prop_C + Prop_A
Output = Prop_C

Really looking forward to any help. Thanks in anticipation!