Repeat a spoken track, every 4th track, in shuffled playlist

[zepsun]

I am trying to coordinate music for a skating event that takes place daily during the week.
I have a pool of about 1000 songs that I want to randomly play, however I need a 'reverse skating' announcement to play after every 4th song.

Looking online I haven't been able to find a way to do this without complicated scripting. I'm trying to automate the music. So far I'm able to use windows task scheduler to start and stop the playlist, but I can sort out the music.

Basically I want something like:

1. All My Love
2. Hello Hello
3. Generation
4. 'Reverse skating'
5. Survivor
7.Dance
8. Rock and Roll
9. 'Reverse skating'
10...etc..

all songs in between 'reverse skating' should randomize day to day.
thanks