farming Farm System

[iRack]

Hi can someone help me? I want to make a plot with Mapping for a farming. I can make the mapping, but i don't know how to make a plot like this: You, as a player, you can buy a small plot. You can own only that small plot where you can plant seeds. And the question is, how can i make the plot? To buy it with a small icon " i " and if you type [/buy] in chat and to take from the player an ammount of money with and OutPutChatMessage ,,You bought it". I want the rules to create it. Thanks a lot!