Using builder and excel files in a loop, issues inserting text pop up on every third image

How to insert a text page into a loop with images being selected from spreadsheet. I have a list of 30 images required to pop up one by one in a loop and every third image I would like to display some text that is unlimited in its time displayed whereas the images are 3 seconds each. Is this possible? Please help as I need to get this functioning in an fMRI by January 3rd :disappointed: