Global and local points in rhino and grasshopper

how to set local coordinates exactly to global coordinates in rhino and grasshopper?

thank you.

what do you mean? How do you define local and global coordinates?

yes i have start pt and end pt of curved bridge they are global coordinates so how to set them in grasshopper?

All coordinates in Grasshopper are global, there’s no concept of c-planes. Of course you’re welcome to treat certain coordinates as belonging to a different axis system, but that’s additional meaning you have to keep in mind.