Matching locations/coordinates in VBA

Question

I am looking for some VBA code (algorithm) to match a list of GPS locations (in this case a ship track) to a given GPS location. That is to say all locations of the list which are located within the circle with a given radius around that location.

See the picture: so only the "green locations" match of all locations. Sorry for the poor picture, handmade in Windows Paint ;-)

All locations are given as latitude + longitude, for example 52.24782, 4.12082.

Answer 1

The function

Public Function CheckCoords(x#, y#, radius#) As String
    ' x^2 + y^2 = r^2
    ' ==> results true if (p,q) fall outside of the circle
    CheckCoords = IIf((x ^ 2 + y ^ 2) < radius ^ 2, "outside circle", "inside circle")
End Function

unit conversion needed for practical implementation

Answer 2

Found this one: http://www.movable-type.co.uk/scripts/latlong.html

I only have to rewrite the code to VBA code and combine it with the code of @Cylian