Secret Exits?

[themasteroftoads]

Through the world map I know that there is secret exit support. I’m primarily using flagpoles from SMB1 as the goals so is there any way to make a secret exit ALSO a flagpole? As I’m making this 1-2 style level, and in a room containing Captain Toad there is also a line of fake, cracked blocks leading to a secret warp pipe. After that, the player must use the ice flower to freeze paratroopas and make some platforms out of them. Then the player gets to the secret flagpole! Please help!