Thank you for the reply. I have looked at the LibPart_Test, but it was from the ArchiCAD 18 DevKit (the one I'm currently using) and it did not had the array example. I assume that the one you are using is the one from the ArchiCAD 19 DevKit.
I will try to get the one from the most recent DevKit, thank you.
//actualSize is the number of characters of every strings you want added plus the number of said strings
//ex: you want two strings "abc" and "st", the value of actualSize will be 3 + 2 + 2 = 7
//to note that the dim1 will still be the number of strings you want, in this example, 2. But you will allocate space for every character plus every separator '\0'.
//the final value of the array will be "abc\0st\0"
int numberOfStrings = 2;
(*addPars).dim1 = numberOfStrings;
(*addPars).dim2 = 1
(*addPars).value.array = BMAllocateHandle(actualSize * (*addPars).dim2 * sizeof(GS::uchar_t), ALLOCATE_CLEAR, 0);
GS::uchar_t** arrHdl = reinterpret_cast<GS::uchar_t**>((*addPars).value.array);
Hope that this can help anyone with the same problem.