In reply to Mark Eddy:
Ah I see what you mean.
As far as I know, pretty much anything that isn't a business meeting or conference will need a visa, although I'm not up to play with French immigration/employment rules.
OP, one option might be to find a UK company that is offering remote work, where you are still working for a UK company/client (not a French one) and simply work remotely whilst you are there. Again I'm not familiar with the details in France, so yiou'd need to check, but it might be acceptable so long as
1. the company/client is not based in France
2. you are not doing business with individuals or businesses in France
3. you don't remain in France (or potentially Schengen) longer than your visa
4. the primary purpose of your trip is for an activity that is permitted on your visa, e.g. climbing/hiking if you are on a tourist/visitor visa
Post edited at 12:23