You want to add additional columns to the destination sheet?
Here is how:
1 Create your connection
2 On the destination spreadsheet, add a blank sheet tab
3 On this blank sheet tab, put the following formula into cell A1:
Adapt the cell
A1 as well as the part
SG_Connection!A:C to match your data range on the imported sheet tab.
4 Add additional columns from column D onward. Obviously, this may vary again depending on the range of your source.
Hope that helps!