see this from SDI:-
|CallingPartyNumber=1067
|DialingPartition=User-Phone-PT
|DialingPattern=4001
|FullyQualifiedCalledPartyNumber=4001
|DialingPatternRegularExpression=(4001)
|DialingWhere=
|PatternType=Enterprise
|PotentialMatches=NoPotentialMatchesExist
please ensure that ext 4001 is in a partition that can be dialed by ext 1067 Calling Search Space (CSS)