How to make a scatter matrix plot in Pandas with specific columns?

I have a csv file with a hundred columns. Imagine it's sales data from a big ISP. Say I just want column "Tier", "Customer Duration", "Satisfaction" and "Region Sales" in my scatter plot. How can I do so?

I have this to read in the data:

ISPSales = pd.DataFrame.from_csv("sales.csv")

The problem is when I do the scatter plot matrix, it becomes an unreadable chart (with over 50 columns, etc)

The Pandas Doc has the following

df = pd.DataFrame(np.random.randn(1000, 4), columns=['a', 'b', 'c', 'd'])

scatter_matrix(df, alpha=0.2, figsize=(6, 6), diagonal='kde')

But that doesn't help on selecting only a few columns from a csv read in style. Help!