Thanks for the help, but I used the script. Also, does putting an $ before names from custom tilesets always help? Cause they don't always fit properly in the database when I download them from here.
You do not need to import the tileset into a character to use the grafics as an event, the B-Tiles and following are automatically available as event graphics even while in the tileset definition, just scroll down the list when choosing an event's picture.
Quite the contrary, just importing the tileset never helps, you'll need to change the tile from the tileset into a sprite picture (which is a lot more preparation work in an image programm like GIMP or Photoshop) before you can use it that way.
And no, putting a $ before the name of character files doesn't always help - it's there for a very specific case (switch between single and 4x2 character sheets), and in all other cases it will not help.