Can I charge my Forerunner 235 in any way except by plugging it into my latop via the charging connector?Negative. You have to use the supplied USB docking/charging cable (or a compatible replacement), but the USB type-A plug on it does not have to be plugged only into a USB port on a laptop.
Is there some way of charging vis an iPad…Negative. The battery in the iPad cannot be used as a power source to charge other device's batteries via a cable connected to the tablet's Lightning or 30-pin connector.
or can I charge it by plugging the charging connector into a powerpoint?Negative. The supplied USB docking/charging cable cannot be plugged into a general/AC power outlet on the wall. You'll rarely find 5V USB charging ports on wall outlet panels, above or completely separate from 110–240V sockets (i.e. “powerpoints”), although I've seen them before once in an odd while, and they're available for sale in some home improvement hardware stores.