Need Help with Understanding GetProperty

I have a module where I have created a series of global properties representing a schedule of entry, as such:

Start1
Start2
Start3
Start4
etc…

I would like to copy the value of each of these properties into another global property, Amount, on the turn the number represents.
So that on turn 1 the value of Start1 is transferred to Amount, on turn 2 the value of Start2 is transferred, and so on.

I have not been able to have GetProperty perform with many varieties of syntax of the statement
GetProperty(“Start”+$Turn$).

Any guidance or pointing to working examples would be greatly appreciated.
I am editing with Vassal 3.2.8.