According to the Cypher reference at http://docs.neo4j.org/chunked/milestone/query-match.html ...
12.2.13. Variable length relationships Nodes that are a variable number of relationship→node hops away can be found using the following syntax: -[:TYPE*minHops..maxHops]->. minHops and maxHops are optional and default to 1 and infinity respectively. When no bounds are given the dots may be omitted.
An example of what I think you seek is below. I set the minimum at two.
start n=node:node_auto_index(name='Neo') match n-[r:KNOWS*2..]-m return n as Neo,r,m
You can test this query verbatim at http://console.neo4j.org