Lovely user interface this isn’t. Here’s the command to make an E1 circuit on a Nortel TN4XE where the E1 card is in slot 13. (The first character should be a tilde rather than a hyphen):
~C N C S6-1-J1-K111&S8-1-J1-K111 S13-1
S6 and S8 are the slots where the aggregate cards are. J1 says to use the first VC4. K111 tells it to use the first VC3, the first TUG2 and the first VC12.
Within an STM-4 there are four STM-1s which equate roughly to VC4s. Within each VC4 are three VC3s. Within each VC3 are 7 x TUG2s. Within each TUG2 are 3 x VC12.