Access the following Settings to add Cellcoms APN:
Settings > Wireless & networks > Mobile networks > Access Point Names > New APN
Then enter all these information :
Celcom 3g internet setting :
Name : Celcom 3G Internet
APN : celcom3g
MCC : 502
MNC : 19
APN type : default
Celcom 3g MMS setting :
Name : Celcom 3G MMS
APN : celcom3g
MMSC : http://mms.celcom.net.my
MMS proxy : 10.128.1.242
MMS port : 8080
MCC : 502
MNC : 19
APN type : mms