VDT2 - portname as string

Hello! I'd like to open and manage VDT2 connections with the portname set as a string. This is apparently only working for COM1 to COM4 where no single quotes are required. Is this intended or am I missing something?

As a workaround, I could simply "execute str" all VDT2 operations, but I want to run some of the code in threadsafe functions which don't yet support "execute". Any help is appreciated!

function id_device()

// results in error message: "Expected the name of an installed port (such as Printer, Modem, COM1, COM2)"
string portname = "'COM10'"
VDT2/P=portname abort,baud=115200,Databits=8,parity=0,Stopbits=1

// works fine
VDT2/P='COM10' abort,baud=115200,Databits=8,parity=0,Stopbits=1

end