Import user selected columns from a text file

Hi,

I'm trying to write a macro that imports a tab delimited text file. The issue I'm having is that the files tend to be pretty big, so I want it to only import the reference columns (from 1 to 6) and channel columns (from 1 to 16) selected by the user.

I've managed to write an inelegant if statement that works for the channel select option but adding in the reference option would give almost 100 different scenarios, so I figured there has to be a better way to do this

I've attached a text file showing roughly how the data is presented in the text file (there are a lot of useless columns but this is the way it's given to me for now) and a file with the macro that I've been using for one option.

Hope someone can help.

Cheers.