Glad it worked OK.

Just to clear sub address up for others reading and maybe using "shortcuts"

In SOME versions if you simply set the sub address to eg "4" it will link to slide 4. However if you then check the sub address you will see that PPT has automatically modified it to something like "284,4,Slide 4". In other versions you can set the sub address to eg "284,," and it works. I would always set the proper full sub address "ID,Index,Title" especially if your users may not have the same version as you.