Yes there is! In the map maker package that you've downloaded there should be a /server directory with a file in it called daimonin_server.exe (you might not see the .exe bit - depends on how your PC is set up). You
should be able to run that file to start your own server.
Then just start up the client as normal but choose the local server option (127.0.0.1) when you get to the "choose server" screen.
Some useful things:
Inside /server/data is a file called "gmaster_file" ... open this with Wordpad (Notepad can have problems with end-of-line characters) and find where it says:
# *


:DM
EDIT: Darn smileys!

Look for where it says:
# *:*:*:DM
Remove the # and resave the file. Now start your server - anyone who logs in can now go into "DM" mode ... type /dm when you are logged in. In /dm mode you can do things like:
/goto /blah/blah/mymap (useful for testing out your maps)
/create 1 50 sword (useful for creating yourself that +50 sword you always wanted)
/addexp <you> <skillnr> 9999999999999 (gets you to lvl 110 really quickly!)