What dimensions required?, How long / high is this fence needed to be?

the only suggestion would be some wrought iron type construction but how big a span you need will depend on how often you need supports.

Eye bolts & tension wires. Using pliers, install a series of 'eye bolts' spaced about 3 feet horizontally & vertically. Thread the tension wire through the eye bolts keeping it taut. Use the heavy gauge gardening wire made specifically for this project. Now you'll have a sturdy & durable structure for your climbers. The wires become invisible once the climbers take hold. Materials are inexpensive at the DIY store. Here is a video.

Gardening Tips: Supporting Climbers
https://www.youtube.com/watch?v=jKygx4uwYsU

Two 2.x 2 inch fence posts with a rigid trellis fencing panel fixed inbetween - but depends what type of climber really - clematis cultivars won't cling to those, they need thinner struts to cling to.

Thank you Bamboo. I do need trellis so that my climbers will go across it but the gap for posts is more than a trellis width. Where I want it to go across is concrete.

Thanks Bathgate, your idea seems the best one! Thank you. I will look at the video.

Hello Grandad G. The length is about 12 foot long from the drive gate post to the other end where it meets the post at the greenhouse. From the gate post after the 12 foot, I have slabs which I can lift to put another post in. I would prefer it to be 5 foot high . I had this idea about closing off the garden from the open drive and would have to leave an opening to walk through where I could have an arch. Up to the slabs is just concrete. I hope you understand my explanation ! Hahaa!

That's where my problem is Seaburngirl ! The first 12 foot of the drive which I want to separate from the garden is 12 foot long. The rest is slabs which can easily be lifted. Thanks for your suggestion.