Hey, I'm having these (hopefully simple problems) with writing in page numbers:

1. I want to write ex. "7-19" in a cell -
Then in another cell I want excel to give the "result" of the interval of,
here 12.

2. Now, if that's possible, I also want to ask this:
In one cell i want to write 2 or more different interval, ex
"7-19, 81-90".

Can I make excel understand what I'm writing somehow? And get the result of
these intervals in another cell, here 21 (12+9)

Any help will be extremely appreciated - thanks in advance, steve.