Converting .txt files into .stl
 

Hello everyone
I have 2-D coordinates of a hill from N-S, E-W, NE-SW, NW-SE sections as .txt files. I have to do 2-D CFD analyses of wind flow over this hill from these sections in OpenFOAM.
To import the geometry into OpenFOAM as .stl file and mesh with snappyHexMesh, I need to convert these text files containing section coordinates into .stl files. I am having trouble about this conversion. How can I do this?
Thanks in advance for your helps.