Whilst RightMove allows you to search in a custom area, it does not show you properties close to "one of many" areas. For example, say you work near Kings Cross. You will want to find a property within walking distance of a tube station, which itself should be a reasonable number of stops from Kings Cross. Rather than searching near each station manually, it would be useful to get a full list of properties matching your criteria.
If I find a place or get bored before finishing this, it might never happen, sorry!