Excel data connections how to store Relative Path?

Hello, I have excel document and use the auto data refresh from txt document.
The path stored is absolute c:\mydocumet\somefolder\someotherfolder\myfile.txt

I need to move my files frequently but I always have my txt files in same folder as excel file.
How can use Relative Paths so they would update from same folder as my excel file?

Excel ribbon -> Data -> Connections- > Properties -> Definition
Does not allow other actions than browse to file, how to store Relative Paths?

I think I need some code to do this, can anyone help?