Allocates a node that can be added to the Exec linked list of labels in the speedbar. This is the only way to allocate a node for this list, you cannot allocate nodes yourself because the SpeedBar class uses a private node structure.
INPUTS
number
Places value in node->sbn_Node.ln_Pri, and is the numeric ID of the button within the bar. Note the current limitation, ln_Pri is a BYTE. This will be addressed, and *posibly* made obsolete and overridden by SBNA_ButtonID.