Ldapsearch problem

Hi
I'm not familiar with ldap and I hope someone to help me.
I need to get some attribute value from ldap DB.
When i run the following command is OK:

ldapsearch -h localhost -p 16611 -x -D cn=user -w passwd -b msisdn=359502479649,dc=MSISDN,DC=C-NTDB "(objectClass=SUBINNSS)" refinmocNAME

the result is

# hlr, 284018910374316, hlr, services, 359502479649, MSISDN.C-NTDB
dn: o=hlr,imsi=284018910374316,ds=hlr,subdata=services,msisdn=359502479649,dc=
 MSISDN,DC=C-NTDB
refinmocName: PPSOCS

refinmocName: PPSOCS is what I need.

Unfortunately "msisdn" from base DN is variable and I am not able to set it permanently.
I have no size or time limit to search in root (dc=MSISDN,dc=C-NTDB) directory.
Is it possible to construct filter to get "refinmocName" attribute value with objectClass=SUBINNSS based on root search (dc=MSISDN,dc=C-NTDB) like:

ldapsearch -h localhost -p 16611 -x -D cn=user -w passwd -b dc=MSISDN,DC=C-NTDB "(&(msisdn=359502479649)(objectClass=SUBINNSS))" refinmocNAME
# extended LDIF
#
# LDAPv3
# base <dc=MSISDN,DC=C-NTDB> with scope subtree
# filter: (&(msisdn=359502479649)(objectClass=SUBINNSS))
# requesting: refinmocNAME 
#

# search result
search: 2
result: 0 Success

# numResponses: 1

Any help would be appreciated.
Thank you in advance.