And be curious enough to try and figure it out, since he does not know the answer.
After playing a bit, with no success, I opened Help under the wrench icon and did a search for link. Turns out you can not create a clickable URL link in a cell.
You can however create one inside a text box or a shape. Just type in the URL followed by a space or almost any punctuation mark. The URL will be auto detected and underlined. You can then tap on the link to Open, Copy, or edit the link's settings, including the URL and display text.
No, you can't lock zoom or prevent scrolling. Well, you could zoom all the way out, then it won't scroll, but things are a bit hard to read then. Though I suppose you could create a very large spreadsheet that filled the whole page with big cells and big fonts. It would have no where to scroll to.
Never mind. That does not work. The spreadsheet itself just becomes scrollable instead of the whole page.