Most of the small DIY jobs I do around the house require a drill – these days a perfectly serviceable corded electric drill can be purchased for less than £40.
http://www.argos.co.uk/product/5016336
You could drill into the concrete fence posts and secure the fixing screws using raw plugs, but I doubt that you would achieve a reliable fixing – especially as a novice with a drill.
My advice would be to drill a hole all the way through the concrete posts and use coach bolts to fix the panels.
If you take this option, you need to work out the required length of the coach bolts (thickness of the concrete post, plus thickness of the wooden panels, plus thread length for the securing nut/washer. You might get way with an 8mm diameter bolt if the panels are not too heavy and will need a minimum of 2 fixings (top & bottom) at each concrete post.
http://www.screwfix.com/p/general-purpose-threaded-coach-bolts-bright-zinc-plated-m8-x-100mm-100-pack/88185
I should add that drilling the concrete posts will almost certainly be a two man job, with one supporting the post (preventing the force of the drilling pushing over the post), especially when drilling towards the top.
You will need to buy a masonry drill bit suitable for the coach bolts.