'EXIT_SAPLL03A_002' problem with fieldsymbols

hello all ,

i have to write some code in the customer exit 'EXIT_SAPLL03A_002'. this customer exit will trigger while creating a transfer order using LT01,LT02 or LT03 transaction . the standard program for all these transactions is SAPML03T . The customer exit EXIT_SAPLL03A_002 is present inside the Standard program SAPML03T. i have to change the storage type indicator value in the internal table imlvs which is present in the standard program SAPML03T.but when i try to access this internal table inside the exit 'EXIT_SAPLL03A_002'.it is showing syntax error as 'IMLVS is not found '.

How can i make use of field symbols in this case ?

can we declare a field symbol as internal table .

my requirement is to change th value of (SAPML03T)IMLVS-LTKZE inside the customer exit 'EXIT_SAPLL03A_002'.

Thanks in advance ,

pavan.