MiniMap Border!

Hi everyone, I am doing a FPS game in that I need a minimap. I did a minimap by using a camera and changing the item's layer and Render Texture And Raw Image. I right a code for camera follow the player and rotate with the player. I show the enemies as a dot in the minimap. Now I want to make the enemies dot to stick (clamp) the border of the minimap when the enemy is outside the range of the camera. I am slightly new to unity and c# so please help me!!! Thanks in advance! :) ....