Efficient way to plot an user selected graph

Hi,

I am acquiring "n" channel data and I need to plot the graph from the data but the channel will be selected by the user. For e.g. Channel 1 or Channel 2 or he can select Channel 1 and 2. I have a solution to this which uses multiple case structures which I know is not the best way to do this. Is there an efficient way to do this. Can somebody point me to a knowledge base 

I have attached the jpg of how I am doing this.

Thank you in advance

Nitin