I am new comer here. I need a favor to make a formula in Excel to create series of number for 14 Digit Check Digit. Here is my requirements-

I have 14 Digit of data [IMEI number] and i want to make the 15th digit as check digit as per Luhn algorithm. For example-

IMEI: 35145120840121

(5x2, 4x2, 1x2, 0x2, 4x2, 1x2, 1x2) = (10, 8, 2, 0, 8, 2, 2)

(1+0+8+2+0+8+2+2) + (3+1+5+2+8+0+2 ) = 44

Luhn Digit : 6

And final digit will be: 35145120840121

**6**

So, how to make the formula in excel? Please help me to find it out. I will appreciate if anybody can help me. thanks in advance. Have a great day!