Column Step Function??

Hello all, how do you write a function to retrieve a cell reference for every, say 4 columns, in one row of data.

Example: Say I'm studying Coca-Cola Company, and I want to analyze 1st quarter sales (only) for every year over a 50 year period. And, suppose all of my data is displayed in one row and it is organized as follows: 1Q-1950, 2Q-1950, 3Q-1950, 4Q-1950, 1Q-1951, 2Q-1951, 3Q-1951, 4Q-1951, ....., 1Q-1999, 2Q-1999, 3Q-1999, 4Q-1999 [i.e., 200 data points]. In order to do my analysis, I need to copy&paste just the 1Q data in a separate row or column. This is quite laborious to do this manually 50 times.

My question is: How do I retrieve just the 1Q data points under one slick function that can be dragged to produce the fifty data points I want to analyze.