Code to find value into a table by 2 criteria (x,y)
First step:

Write down your assumptions

These would be mine;


This data table has a header row in row 1 and a header column in column A.
The values in the headers could be any legal text.
The values in the headers are unique




What's the fastest way to find an exact match in a list?

My answer: A dictionary (or any other Linked-List object)

Dim rowList as Scripting.Dictionary, columnList as Scripting.Dictionary
    Set rowList = New Scripting.Dictionary
    Set columnList = New Scripting.Dictionary

    finalrow = Cells(Rows.Count, 1).End(xlUp).Row
    finalColumn = Cells(1, Columns.Count).End(xlToLeft).Column

Dim cellText As String

    For i = 1 To finalrow
        cellText = Cells(i, 1).Text
        rowList.Add cellText, i
    Next i

    For i = 1 To finalColumn
        cellText = Cells(1, i).Text
        columnList.Add cellText, i
    Next i


Now we have 2 dictionaries, where each row/column (i) is referenced by its cell value.

rowList.item("0") will return row "5", "100" returns row "6" and so on. This will work with any size of table and any possible values for the headers, so long as there are no repeated values.  

Now you just take your 2 input values, access the associated items, and either they exist and you have your co-ordinates, or they don't exist, and you can tell your user. 

For added speed, read your row/column into an array before iteratively adding them to your list.

Bonus: Aside from the initial time to create the lists, searches are effectively instant for any size of list and any number of searches.