using snmpget() function in PHP to pull a spesific OID form a third-party MIB file

Ip-Watch

Hi all ... i've been working on this for 3 days now searching all the web with no luck ...

I need to pull an SNMP info from a device using snmpget() function (or whatever valid function) and that device is having it's own third-party MIB library/file ...

let me give you som exampels:

$mysnmp = snmpget("11.22.33.44", "plubic", "system.sysDescr.0");
echo $mysnmp;

it returns the sysDescr value perfectly ...

now my reall OID is this :
.iso.org.dod.internet.private.enterprises.clarent.mgt.callmanager.cCMStatus.cmPortInUseCount

Or this:
.1.3.6.1.4.1.2858.100.40.1.1

whenever i try to give the folowing code i get an error:
$mysnmp = snmpget("11.22.33.44", "plubic", ".1.3.6.1.4.1.2858.100.40.1.1");
echo $mysnmp;

the MIB file is called CALLMGR-MIB.mib ...

here is the begining of the file:

CALLMGR-MIB DEFINITIONS ::= BEGIN

IMPORTS
   IpAddress, Gauge, TimeTicks
      FROM RFC1155-SMI
   DisplayString
      FROM RFC1213-MIB
   OBJECT-TYPE
      FROM RFC-1212
   TRAP-TYPE
      FROM RFC-1215;

clarent OBJECT IDENTIFIER ::= { enterprises  2858 }
mgt OBJECT IDENTIFIER ::= { clarent  100 }
callmanager OBJECT IDENTIFIER ::= { mgt  40 }
cCMStatus OBJECT IDENTIFIER ::= { callmanager  1 }
cCMConfig OBJECT IDENTIFIER ::= { callmanager  2 }
cCMSystem OBJECT IDENTIFIER ::= { callmanager  3 }
cCMTrapParms OBJECT IDENTIFIER ::= { callmanager  4 }
cCMPorts OBJECT IDENTIFIER ::= { callmanager  5 }
cCMPortStatus OBJECT IDENTIFIER ::= { cCMPorts  4 }
cCMPortControl OBJECT IDENTIFIER ::= { cCMPorts  5 }
cCMStatsTotals OBJECT IDENTIFIER ::= { callmanager  6 }
cCMClass4 OBJECT IDENTIFIER ::= { callmanager  7 }
cCMBlades OBJECT IDENTIFIER ::= { cCMClass4  1 }
cCMSpans OBJECT IDENTIFIER ::= { cCMClass4  2 }
cGIFLinkStatus OBJECT IDENTIFIER ::= { callmanager  8 }
clarent-cmtraps OBJECT IDENTIFIER ::= { callmanager  100 }

cmPortInUseCount OBJECT-TYPE
    SYNTAX  INTEGER
    ACCESS  read-only
    STATUS  mandatory
    DESCRIPTION
           "Number of ports currently in use"
    ::= { cCMStatus  1 }

i need to pull the info for this object: cmPortInUseCount

So my question is:
How can i write the correct snmpget() code to retrive this OID ?

Any help please ?

thanks a lot ..