RM/COBOL -- Passing Data to Cobol Program

HI - 

I have file that contains 1 record but the length of data can be from 2 chars to 700,000 chars.  I want to access such file in RM/COBOL program, ran via shell.

Neither FD section approach nor sending via LINKAGE section is working. Using XML  IMPORT FUNCTION. Is there any other oway to pass the data. Something like reading file in shell, pass address of data to cobol program, and   Cobol access via address if possible. [Looking for utilityC CRG or DARG].