If you know the number of the node you want to connect to simply press those numbers on your DTMF Microphone or Dialler, for example 57007 will connect you to EI2MOG which is a 2m Gateway on 145.2125.
Here are other commands you may want to use:
00 – Connect to a Random Station.
01 – Connect to a Random Repeater/Link.
02 – Connect to a Random Conference.
03 – Connect to a Random User.
# - Disconnect last Station.
# # - Disconnect all Stations.
09 - Reconnect last Station.
08 - List all Stations currently connected.