How to find 2 values record in table?

I'm creating Google Sheet for work, and have problem with advanced formula.

I have one table:

Country 1:  Postal code 1:  Country 2:  Postal code 2:
AT          2341            BE          BE4523
DE          D34215          DE          D34215
BE          BE4523          AT          2341

I have to merge Country 1 and Country 2 with only 2 digits (f.e. DE34 not DED34) and find this linked in such value table:

        AT23    DE34    BE45
   AT23 -       0,15    0,13
   DE34 0,15    -       0,20
   BE45 0,13    0,20    -

For example, in the first record, I have to find AT23 + BE45, and fill a cell with value 0,13.

Is it any solution for that?