There are probably a fintite number of points that are your best guess and near a station. Use station locations inside a radius. Then run them all through map

There are probably a fintite number of points that are your best guess and near a station. Use station locations inside a radius. Then run them all through mapumental to get distances. Weighting can be done in code or a spreadsheet. Or implement a hill climbing algorithm using mapumental and the weights to make your cost function.