Use Values From Two Columns To Retreive A Third Value

I have been trying without success to use Vlookup to lookup a value in one column, say the number 15. 15 in this column will fill cells in several rows as it refers to several different values in the second column. The second column only has one instance of each value, for example 42. Then with this information I have been trying to get Excel to retrieve a third value and return it to the cell from which I am entering

the formula......An example...
15............. 42 ................ yellow
15............. 42.5 ............... blue
15............. 43 ............... red
16............. 42................... purple
16............. 42.5................. green
16............. 43.................... pink

Is this asking too much of VBA? I don`t think so but cannot figure out how to properly enter a formula that will do this. I have tried Vlookup several different ways with no success. If I could get it to return the cell reference instead of the cell value on the first lookup excersize I could then make the second vlookup start at this cell reference to get the third number but I can`t even figure out how to do that.