Your destination path is wrong it would turn out to be
\\192.168.1.2\\sabre\\Mapping Rules Upload\\<filename>
you need 1 slash in each directory seperator
You either need
string destFilename = @"\\192.168.1.2" + @"\sabre\Mapping Rules Upload\" + fileName + "";
or if you remove the "@" then you need to escape each "\" with another "\"
string destFilename = "\\\\192.168.1.2" + "\\sabre\\Mapping Rules Upload\\" + fileName + "";
The @ sign just saves you escaping chars that require escaping in a string!
EDIT: I am presuming that in your code fileName and filePath are set correctly!
HTH
OneSHOT