I have the best way :3
Step 1: Open Notepad
Step 2: Paste this code in. start BlocklandLauncher.exe -dedicated -map bedroom
pause
Step 3: Save as dedicated.bat in your C:\Program Files (x86)\Blockland (Make sure you change the "Save as type" to all files)
Step 4: Double click on that file.
Step 5: Enjoy.