Copy records from one subform to another using function

Copy records from one subform to another using function

Hi 

I have 2 parent forms with the same subform, the subform also contains lookups to the parent forms.

In the first parent form I have a function that lets me copy over the records to the second, this works for all the standard fields, I'm having problems copying over the subform rows/data.

1. How do I 'access' the subforms fields for the function, at the moment I have something similar to this:

void copyRecord(string First_Name, int CountryID)
{
    insert into Parentform_2
    [
      First_Name = input.First_Name
      Country = input.CountryID
    ]
}

Where do i add the insert into for the subform? How should this be structured?

2. What are the argument types for the dropdown and multiselect in the subform, so I can add them to copyRecord?

Been going round in circles with this so any help would be greatly appreciated, Thanks!