Panoramic, meaning 360 degrees spherical panoramas?
Bare Construct 3, I can think of two ways:
-mesh distort a Sprite to create a sphere (look for R0J0Hound's experiments thread - he has an example file there) - then set up a 3d Camera and rotation controls so you can pan around the panorama - this does not require any conversion to your panoramic image.
-convert your panorama into a box map ("skybox"-type) - map it into a Box 3d Shape and again, set up actions in the 3d Camera for panning of the view.