How to do it...

1. Create a new C++ class derived from the StaticMeshActor class using the editor wizard; call it SlidingDoor.
2. Add the following text that's in bold to the new class:

class CHAPTER_09_API ASlidingDoor : public AStaticMeshActor
{
    GENERATED_BODY()
    
public: 
    // Sets default values for this actor's properties
    ASlidingDoor();

protected:
    // Called when the game starts or when spawned
    virtual void BeginPlay() override;

public: 
    // Called every frame
    virtual void Tick(float DeltaTime) override;

    UFUNCTION(BlueprintCallable, Category = Door)
    void Open();

    UPROPERTY()
    bool IsOpen;

    UPROPERTY()
    FVector TargetLocation;
};

3. Create the class implementation by adding the following text in bold to the .cpp file:

#include "SlidingDoor.h"
#include "ConstructorHelpers.h"

// Sets default values
ASlidingDoor::ASlidingDoor()
{
    // Set this actor to call Tick() every frame. You can turn
    // this off to improve performance if you don't need it.
    PrimaryActorTick.bCanEverTick = true;

    auto MeshAsset = ConstructorHelpers::FObjectFinder<UStaticMesh>
    (TEXT("StaticMesh'/Engine/BasicShapes/Cube.Cube'"));

    UStaticMeshComponent * SM = GetStaticMeshComponent();

    if (SM != nullptr)
    {
        if (MeshAsset.Object != nullptr)
        {
            SM->SetStaticMesh(MeshAsset.Object);
            SM->SetGenerateOverlapEvents(true);
        }

        SM->SetMobility(EComponentMobility::Movable);
        SM->SetWorldScale3D(FVector(0.3, 2, 3));
    }

    SetActorEnableCollision(true);

    IsOpen = false;
    PrimaryActorTick.bStartWithTickEnabled = true;
}

// Called when the game starts or when spawned
void ASlidingDoor::BeginPlay()
{
    Super::BeginPlay();
}

// Called every frame
void ASlidingDoor::Tick(float DeltaTime)
{
    Super::Tick(DeltaTime);

    if (IsOpen)
    {
        SetActorLocation(FMath::Lerp(GetActorLocation(),  
                                     TargetLocation, 0.05));
    }
}

void ASlidingDoor::Open()
{
    TargetLocation = ActorToWorld().TransformPositionNoScale( 
                                                   FVector(0, 0, 200));
    IsOpen = true;
}

4. Compile your code and launch the editor.
5. Drag a copy of your door out into the level:

An easy way to have objects fall to the ground is by using the End key with the object you want to drop selected. 

6. Make sure you have your SlidingDoor instance selected, then open the Level blueprint by going to Blueprints | Open Level Blueprint. Right-click on the empty canvas and expand Call function on Sliding  Door 1:

7. Expand the Door section and then select the Open function:

8. Link the execution pin (white arrow) from Event BeginPlay to the white arrow on the Open node, as shown in the following screenshot:

9. Play your level and verify that the door moves up as expected when Open is invoked on your door instance: