Here is the modem script that will probably work. No promises. Make sure the text is exactly as below. No fancy quotes, no nothing extra, just plain text.
! LG CU500 MODEM SCRIPT
!
!
@ORIGINATE
@ANSWER
serreset 1843200, 0, 8, 1
write "at+cgdcont=1,\34IP\34,\34wap.cingular\34\13"
write "atdt*99#\13"
@HANGUP
exit 0