Selectively Picking Duplicates

I'm trying to get Excel to do a certain function, I'm not sure if it can be done with normal functions/formulas or if it requires programming. But basically, here's what I need to do:

There are several B column coordinates that I want paired up with A column coordinates. For example, column B has 4 duplicate entries of 40, and column A has 1000, 1010, 1020 and 1030. I want Excel to selectively choose only the row that contains 40, 1000. Then let's say the next 8 rows are all 41 in column B, and column A has entries of 1005 (we'll just say 1005 is the lowest number), 1006, 1092, etc. and so on. Again, I want Excel to selectively choose only the row that contains 41, 1005. The farthest I've gotten is sorting the columns in ascending order so I can visually see the coordinates, but is there a way to get rid of all the other duplicates (such as 40, 1010 and 40, 1020, etc.) so that my final spreadsheet will have no duplicates in column B? I would do it manually but there are over 400 numbers each with a varying number of duplicates (ie: I have four duplicates of the value 40, ten duplicates of the value 41, etc.) paired up with numbers in column A. I was wondering if that was a function that could automatically pick the lowest number in column A associated with each different number in column B.

I hope that was clear enough, but I can try to be more specific if need be.

Try this macro

Sub Test()
For N = 1 To Cells(65536, 1).End(xlUp).Row
    If N = 1 Then
        Cells(65536, 4).End(xlUp).Offset(1, 0) = Cells(N, 1)
        Cells(65536, 4).End(xlUp).Offset(0, 1) = Cells(N, 2)
    ElseIf Cells(N, 2) <> Cells(N - 1, 2) Then
        Cells(65536, 4).End(xlUp).Offset(1, 0) = Cells(N, 1)
        Cells(65536, 4).End(xlUp).Offset(0, 1) = Cells(N, 2)
    End If
Next N
End Sub

Open up the VBA editor by hitting ALT F11

Insert a new module by hitting Insert - Module

Paste the macro into the empty sheet

Hit ALT F11 to get back to the worksheet.

Run the macro by going to tools-macro in Excel 2003 or the view ribbon in Excel 2007.