Hi Everita,
So am I right in understanding that you have curved lines on a storey/drawing that you are referencing into your current storey/drawing and you wish to use those curved lines to generate a mesh. The curved lines
If this is so then -
With the trace showing the curves you wish to use.
Activate the mesh tool and set up as required.
Hold down the spacebar and pass over the curves and mouse click.
Ideally the curves need to form a closed shape, if not AC will close the mesh for you, if the shape generates a self intersecting shape AC may have problems.
I hope I have understood the issue.
AC 17
Windows 7 Pro
Intel i7-2600
16GB RAM