Creating a function to select and copy data automatically

[NavRee]

If the output file has the following:
Column A= time
Column B = BP
Column C = TCD
Column D = marks

For 99% of the rows, “marks” has no data (or a dash or some form of place holder.  Then it indicates “start” and later on it indicates “stop”. Is there any way to use the "IF command" to make excel copy data from columns B and C into column E and F, from the start point to the stop point? Or, what would be the best approach?

[#2]

With your permission, if I can recommend you, add a file (without sensitive data) to your project.
Explain your plans in relation to this file. So you can get a solution that is tailored to your needs much faster.
At the same time, it is much easier for someone who wants to help to understand the subject.
A win-win situation for everyone.
Please no Picture, even if it is said that a picture can say a thousand words, it is certainly not in the case of Excel, on the contrary in some cases.

* Knowing the Excel version and operating system would also be an advantage.

Thank you for your understanding and patience

Nikolino
I know I don't know anything (Socrates)