The built-in Timeline Chart template in Google Sheets is great and very useful as it's very easy to read daily values. However am I correct in saying that it is restrictive in the amount of editing that can be done?

For example, I can't put a £ sign before the figures or show £4 000 000.67 as anything other than 4000000.67

I could switch to Excel - I have a 365 subscription - but I don't think they have that type of graph.

Any help or comment would be gratefully received - my presentation is looking a bit amateurish at the moment...