Ok, don't feel bad that I "tell you I do it all the time", but I don't tell you how to do it. So here it goes: Make your straight side of the platform making sure you set the desired height with exact parallel to the straight track. Have the curved track already set exactly as you want it. Now make a platform near the station. Make it for a near length as you want it to be. The key here is to use the shift key so the splines don't lock. So, move one end of the curve to be platform so it matches the end of the straight one while keeping the shift key depressed. Set it exacly at the end and at the right distance to the curved track. Extend or move the platform to the center of the curve or half way to the other end. Start another section of platform from the center of the curve (end of previous half section of platform) to the other end, again with the shift key depressed. Now move the center spline circle away or near the track so that the distance is as close as it should be. The curved platform should maintain a curved front to the track with about the same curvature. If the new platform is too high or too low, use the "get spline height" and "apply spline height" tools to match. Bear in mind that you can overlap splines so that one is "inside" of the other, but to prevent locking, the shift key must be depressed. Another variation of this, is to almost superimpose the platform to be curved over the staright one. Insert a spline point at the middle and move it towards the track (curved center), then make adjustments until all is right. Hope it satisfy your need, and let us know the outcome.