I think the problem is that your data isn't organized appropriately.
I think you're looking for a graph something like this:
Your data is organized with your X value in the Column names and the Y values in each row. Instead you need XY pairs in rows a column to identify the "Row".
JMP makes it easy to reshape the data this way. Start by adding a new column to you table to hold the "Row" number.
Go to Cols->New Column... and complete the dialog naming the column Row, filling it with Sequence Data and adding the column before the first column.
Next you'll want to Unhide and Unexclude all the columns that you've got hidden and excluded.
Then, go to Tables->Stack and you can stack all your 400-900 columns.
You'll get a table with three columns and 2000 rows.
Now you'll need to change the data type of the Label column to Numeric and the Modeling Type to Continuous.
Now you can go to Graph Builder and drag the Label column to the X axis and the Data column to the Y axis and Row to the Overlay role.
If you want only the range 400-500 you can rescale the axis or use a Local Data Filter on the Label column to exclude Labels greater than 500.
-Jeff