I won't claim to be an expert on regexps, but here's my 2 cents. First, lets go through the ones you posted.

$var =~ /n\\(.?)\\/
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will match "{anything}n\{one or zero characters}\{anything}", and $1 will contain the "{one or zero characters}".
The dot matches one character, the ? modifies that to match zero or one times. Because it's enclosed in parens, it'll store it.

The second regexp you showed will match "{anything}n\{anything except \}", and $1 will contain the "{anything except \}".

Now, to get the match you're looking for, something like:

$var =~ /n\\(^\\]+\\/;
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which will match "{some text}n\{some more text}\{and even more}" and store "{some more text}" in $1.
What this regexp does is looks for 'n\' followed by one or more characters that aren't a '\', followed by a '\'.

Hope this helps. =]