excel - add same text every 10th line, possible?

[8ball]

Have a list of 5k items in the excel, is it possible to add a new text item (%VARIABLE%) every 5-10th line or so?
Or any other programs out there that can do this?

So it would look like:

line 1
line 2
line 3
line 4
line 5
%VARIABLE%
line 6
line 7
line 8
line 9
line 10
etc

Thanks

[8ball]

bump .. 1

[grumpy]

cant you record key strokes and then play them back 500 times or so? like making it a macro?

[96ukssob]

i can probably do it if you send me the file. if you are trying to do what im thinking its pretty easy but harder to explain