INDEX MATCH Help!

Hi Everyone 

Wonder if someone could help me out :)

I have tried (using google but i think I'm misunderstanding the logic)

On Sheet one i have 2 columns 'C' and 'D' are Lists (generated from column A and Row 1 on 2nd sheet (mileage Chart in this post)

What i want to do is return a value from sheet 2(Mileage Chart) based on the selections of C3 and D3 lists.

My 'Mileage chart is setup as a matrix

I have tried the following but can't get it right as you can see from my image i get #Value error!

=INDEX('Mileage Chart'!A1:AP43,MATCH(C3&D3,'Mileage Chart'!A1:AP1&'Mileage Chart'!A2:A43,0))

Any help would be appreciated

Gary