Loop until element exists, the continue execution

I have a long script (VB6) that fills in a form.

In a certain part, the user must import a file and must click "Next" to continue.

I would like to wait for this user input and then continue executing the script.

When the user clicks "Next", a new page will appear and there are some unique elements. I want to continue executing the script based on the existence of one of these elements.

I have been reading about using Do..Events... but some others suggest a combination with Sleep.

Please advise what would be the best?

Thanks!