If all you need is to directly create these sprites, simply keep a reference to the sprite collection data object (not the sprite collection object, as that will include the source data), and you should be able to create sprites in the scene.
You can do this by storing a prefab and creating it, or simply adding a sprite component to a gameobject like so -
var boundsData = spriteCollectionData.FirstValidDefinition.untrimmedBoundsData;
Bounds bounds = new Bounds(boundsData[0], boundsData[1]);
GameObject go = new GameObject();
go.transform.position = new Vector3(bounds.extents.x * 2 * positionX, bounds.extents.y * 2 * positionY, 0);
tk2dSprite.AddComponent(go, spriteCollectionData, spriteId);
where spriteId is the id of sprite you wish to create based on your external data.
Hope that helps. Feel free to ask if you have any further questions.