Data Validation Limitations- Shortened Formula

I am trying to use the validation feature to calculate a check digit and the formula is too long to put in validation. I rewrote the formula to be shorter using math features instead of text, but apparently you can't use arrays in validation. Because of certain distribution constraints, using VBA is not possible so a UDF is out. Can either of these be shortened in anyway? I am not sure if it is even technically possible to solve this problem with these constraints.

Here is the "human readable" explanation of formula:
(Accept only 10 digit numeric value.)
Example Number: 123456789-3
Digits 1,3,5,7,9 are multiplied by 2 (weighted 5)
So 1,2,3,4,5,6,7,8,9 becomes 2,2,6,4,10,6,14,8,18Weighted 5's multiplied values then have their individual digits added (ex:12=1+2=3)
So 2,2,6,4,10,6,14,8,18 becomes 2,2,6,4,1,6,5,8,9
Weighted 5's sum is added to the sum of the Nonweighted 4 digits.
So 2,2,6,4,1,6,5,8,9,3 becomes 43
Add 24 to sum.
43+24 = 67

Checksum = (10-(67 mod 10)) mod 10
(Sum round up to 10 minus sum)

Method 1 ...