Hi I am looking to install a new dual flush toilet at my home.

The old toilet looks like the piping out is connected directly out to the wall.
The house is built on a concrete slab

Most toilet models seem to have the piping going out through the floor first.

I am wondering if our system will cause a problem for new toilet installation?

Sorry I don't know much about toilet installation so I hope I have described it OK.

Would much appreciate any help.

Be more specific: what "piping" is connected to the wall? Water or Waste ? Back to you...

The old toilet looks like the piping out is connected directly out to the wall
Sounds like you have a rear discharge toilet. Is it wall hung, (see image) or floor mounted? Are you doing the work yourself? Can you furnish more details plus a picture? Regards, Tom