The WriteVirtualPortVariant method writes data stored in array of VARIANT type to virtual serial port at any time.  

LONG WriteVirtualPortVariant(
 VARIANT Buf // data buffer

  Buf – [out] Pointer to the buffer that receives the data read from the serial port.
Return Values
  The WriteVirtualPortVariant method returns the number of bytes to write to the port.

 This method should be used in IDE (VB, C#), which are not able to work with pointers.

VB.NET example:

 Dim Buf(3) As Byte
AxSpsax. WriteVirtualPortVariant (Buf)

C# example:

 byte[] Buf = new byte[10];
AxSpsax. WriteVirtualPortVariant (Buf);