i have 30 slides, which one is specifically i need to change its text content everytime it rolls. Can this be done? if so how?

I don't even mind making up 50 slides, as long as that one chooses a different slide each time it rolls round. so 29 are the same the 30th is different.

Can powerpoint do this?

Ideally to save work, i just want to have it look at a text file and choose the next line down to display.

But i really don't mind as long as it can be achieved without me having to make up a 400 slide presentation where 290 of them are 100 copies of 29 slides.