I hope you dont mind a c-script; I made the exact same effect for another RE like game couple of weeks ago.

Code:
function blinkingItem() {
	you = ent_create("spark.pcx", my.x, NULL);
	you.BRIGHT = on;
	you.PASSABLE = on;
	you.transparent = on;
	
	var scaleFac = 1;
	var timerCount = 32;
	var timerWait = 0;
	
	while(me) {
		vec_set(you.scale_x, vector(scaleFac, scaleFac, scaleFac));
		vec_add(you.pan, vector(0, 0, 0.5)); // make it rotate
//		you.alpha = scaleFac * 100;
		
		timerCount -= 1;
		if(timerCount <= 0) {
			scaleFac -= 0.05;
		}
		
		if(scaleFac < 0) {
			timerWait += 1;
		}
		scaleFac = cycle(scaleFac, 0, 1);
		
		if(timerWait == 3) {
			timerWait = 0;
			timerCount = 32; // 2 second delay
			scaleFac = 0;
		}
		
		wait(1);
	}
}



Call this function on whatever item you want to shine. And also make a spark.pcx file for the flashy effect.

hope that helps!

regards,


Formerly known as dennis_fantasy
Portfolio - http://www.designorhea.com/
Project - http://randomchance.cherrygames.org/