Help!!!

I've tried everything but can't get the formula I need to do the following:

I have a table as follows

40 43 45 49
Group 1 10 20 30 40
Group 2 12 22 32 42
Group 3 14 24 34 44

On my spreadsheet I will manually input a Group number and also the value 40 (or 43,45,49). Now in another cell, B1 I want to create a formula that looks up which group I have typed in cell A1 e.g Group 2 and looks up which numeric value if I typed in cell A2 e.g. 43. I want the formula to return the answer 22 in cell B1.

Please please can anyone help. I have tried Index's, Match's, Arrays. I am 80% there but can't finish!!!!