Excel formula to return last xth numeric value from row

Question

I have a data set like this:

a   1       2   3       5       6   7
b       5       1   3   4           
c   7   4       3   2       6       
d   1   2   3                       7
e   7   5               5   6   7   

which i want to transform in excel to only show the last 4 numeric values for each row, ie

a   3   5   6   7
b   5   1   3   4
c   4   3   2   6
d   1   2   3   7
e   5   5   6   7

Ive managed to use =INDEX(row1,MATCH(9.99999999999999E+307,row1)) which correctly returns the last value (ie 7 for row1 in this case) but how could i get the 2nd last, 3rd last, 4th last etc?

Answer 1

With a in A1, in M1 copied across and down to suit:

=MID(RIGHT($B1&$C1&$D1&$E1&$F1&$G1&$H1&$I1&$J1,4),COLUMN()-12,1)

then hide ColumnsB:L.

(Only works for single digits, as shown. Recent versions of Excel may offer better options.)

Answer 2

So I managed to figure out how to do this generically for any digits:

Say your original numerical data is in cells D5:N9 .

OPTIONAL:
If any of the rows of data contain the same value twice create a copy in cells D13:N17 which amends duplicates slightly by using in D13 and dragging to fill
=IF(D5="","",D5+0.0001*(COUNTIF($D5:D5,D5)-1))

Then in cells A13:A17 enter values 13 , 14 , 15 , 16 , 17
and in cells A20:A29 enter values D , E , F , G , H , I , J , K , L , M

In Cell D20 you can return the last from row 13 value using:
=LOOKUP(9.99999999E+307,D13:N13)
and copy this down for each row.

In Cell E20 you can return the 2nd last entry using =LOOKUP(9.99999999E+307,$D13:INDIRECT(CONCATENATE(INDEX($A$20:$A$29,MATCH(D20,$D13:$N13,0)-1),$A13)))
and copy this down for each row and drag it across to H24 to fill in all the values for 3rd last, 4th last and 5th last for each row.