If I remember right: it did not used to be possible to create new variables, especially arrays, in a compiled environment. (other than considering a 2D array as an array of arrays)
However, I just ran a test: I executed this code in a compiled environment: and it worked:
INSERT IN ARRAY($Ptr->;1;5)
ALERT(String(Size of array($Ptr->)))
Can anyone tell me: how long has it been possible to dynamically create arrays in compiled environment?