When SM in Spectrum Analyzer mode it available only from LAN side. If you have remote access to PC in same network segment with SM, you can use ssh tunnel.
example for Linux: ssh root@172.22.121.164 -L 8001:192.168.0.3:8001 javaws ~/Downloads/ePMP-1000-Spectrum-Analyzer-Tool.jnlp (If needed: sudo apt-get install icedtea-netx)
For Windows you can use Putty (Putty>Connection>SSH>Tunnels)