+5  A: 

In cygwin's bash, you need to escape any of those forwardback slashes, as those are interpreted as escape characters.

try this

net use /user:"Someone" \\\\server\\share

or use single quotes, which will pass the argument unchanged

net use /user:"Someone" '\\server\share'

karoberts
Minor correction: Need to escape backslashes. \ backslash, / forward slash.
shoover
@shoover I always forget which is which, thanks for the correction
karoberts