Create user log-ins using excel data

I have data downloaded from excel. The data is in 3 columns. (first name,last name,birth year). I want to create a function that creates an ID using the first letter of the first name, the whole last name, and the last 2 digits of the birth year.

I am able to read the data and export it to mat lab:

[numberdata,textData,allData]=xlsread('children')
numberData=xlsread('children','Sheet1')

But I am lost after that.

[Walter Roberson]

hint: last 2 digits of a year is mod(year, 100)