Hi David, Yes I know i was a bit vague. What I need is a simple function, that can turn a point in GPS - a lattitude and a logitude value - into a point in GIS. I.e. I got these coordinate: GPS: N: 54.9809 E: 8.86707 that applies to GIS: X: 491055.41 Y: 6092507.928 What I need is the correlation between the two. Regards Peter