I am currently learning how to use Figma.
Here's an exercise I've set myself:

A square frame serves as the base for an iOS app icon.

Inside the frame, I've created 10 vertical auxiliary line at equal intervals.

Now I want to enlarge a vector graphic in this frame so that it takes up the full width between lines 2 and 9.

So far, I have been doing this laboriously by hand, making sure that the boundaries of the vector graphic snap to the guides.

Is there an easier way? With a single command such as "Expand to maximum width"?

Additional question:
Is it possible to implement the concept of padding in a frame?

Thank you.