Hi la6yba,
according to the user guides published in CPI for MX-One TSE V5, the procedure is unchanged.
i.e.
External calls on individual external line
• Lift the handset (dial tone).
• Dial the access number.
• Dial *0* individual external line number# external destination code and external number.
Perhaps you are doing something wrong or have the wrong trunk number for the assigned dest.
For example, if you have dest=0 and the route is 9 with trunk number 1-1 to 1-30, if you want to access trunk number 1-12 you will dial-
*0*112#0 followed by the number you want to dial.