//prepare transformation of mate
Matrix3D oTransformation = new Matrix3D();
oTransformation.OffsetX = 20.0;
oTransformation.OffsetY = 20.0;
oTransformation.OffsetZ = 0.0;
//prepare description of mate
Eplan.EplApi.Base.MultiLangString oDescription = new Eplan.EplApi.Base.MultiLangString();
oDescription.AddString(ISOCode.Language.L_en_US, "User defined mounting point number 001.");
//create new point mate object
PointMate oPointMate = new PointMate();
#pragma warning disable 0618
oPointMate.Create("UserMate001", "*", oDescription, oTransformation);
#pragma warning restore 0618
//assign mate to 3D placement
oMP.AddMatePersistent(oPointMate);
//find the new mate
var oUserMate001 = oMP.FindTargetMate("UserMate001", false);
//remove the mate
oUserMate001.Remove();
//oPlane.FindTargetMate("UserMate001", false) == null