Sharing Global Variables between Modules

Hi All,
I have 2 modules in a program. Each one /copies in a standard
3rd party data structure definition and it is not qualified. The DS is
global in each module. Each module can update the DS. I need to pass
this DS between modules and have any updates reflected in the calling
module.

Here is an example with I00SC as the global variable.
CALLER:
P5992101V1_AskEnv( Rec:I00SC) ;

CALLEE:
P P5992101V1_AskEnv...
P B export
D P5992101V1_AskEnv...
D PI
D Rec likeds(F5992101_t)
D XI00SC Likeds(I00SC)
/free
I00SC = XI00SC ; // initialize DS
....MODIFY I00SC HERE
XI00SC = I00SC ; // populate return DS
Return ;

There must be a better way than that. Passing a pointer around maybe?
An example would be appreciated.

Thanks...
- Steve