Hi,
Need some more info...
Will you always want to access this server from the same location (e.g. your office PC) or from anywhere (e.g. internet cafes, friends houses etc).
If always from the same PC then go for a VPN solution as suggested above, or lock down your SSH access to the SME with certificates, and SSH tunnel your connection to ZoneMinder.
If you need access from anywhere, then you can either SSH tunnel as above (Carry your SSH client & key on a USB stick - this is what I do)
or
portforward / proxypass your connection to Zoneminder. Note however that this is not generally recommended as anyone could theoretically access your zoneminder system.