void axSignApi4_OnGetDeviceXMLCertificate(object sender, IStepOverSignatureAPIv4Events_OnGetDeviceXMLCertificateEvent e)
{
    e.certificate = SigDev.GetDriverString(3);
}

Private Sub signapi4_OnGetDeviceXMLCertificate(ByVal Certificate As Object)
        Certificate = mSignaturDevice.GetDriverString(3)
End Sub

procedure TForm1.SignApiGetDeviceXMLCertificate(Sender: TObject; TypeOfPic: Integer; out Certificate: OleVariant);
begin 
	Certificate := StepOverSignatureDevice1.GetDriverString(3);
end;

Private Sub signapi4_OnGetDeviceXMLCertificate(Certificate As Variant)
    Certificate = sigdev.GetDriverString(3)
End Sub