Dim GeodeticSRID As Integer = 4326

'You will need to look up your UTM Projection SRID in the attached projections RTF Document.

Dim UTMSRID As Integer = 0

Dim UTMtoGeodetic As New Proj4Projection(0, 4326)

Dim ProjectedVertex As Vertex = UTMtoGeodetic.ToProjection(YourXCoord, YourYXoord)

MsgBox(ProjectedVertex.X)

MsgBox(ProjectedVertex.Y)