I think I might have given you guys a bad example.
There could be anything in the current cells and I need to insert "TEXT"
after every 5.
Lets try again:

I need to go from this:
apple
orange
widget
7845
santa
34blue
test
witch
never
45hold
74more

to this:
apple
orange
widget
7845
santa
TEXT
34blue
test
witch
never
45hold
TEXT
74more

Regards
Mike