QGYOLSPL & QGYGTLE APIs

I'm wanting to write an RPG IV program that will monitor an output queue for
spool
files, and if there are any in the queue to e-mail the spool file to a
users.  E-mailing
a spooled file is no problem, as long as I know the spool file information.

I am attempting to use QGYOLSPL (Open List of Spooled Files) and QGYGTLE
(Get List Entries) API's to do this.  I very seldom write API headers and
this one
has me a little baffled for the QGYOLSPL API.

There are only 9 paramenters, the first 2 which are:
Receiver Variable - Output Char (*)
Length of Receiver Variable - Input Binary (4)

Normally, for an error code it is defined as Char (*) and I just put the
fields
I want to get returned in the data structure for the API call.  Usually the
first field or two of the structure has the length of the structure for the
error code, so the system knows how much data to pass.

But, since the Receiver Variable is the first paramenter, and the length of
the receiver variable is the second paramenter, I'm thinking this won't
work.
How is the API call going to know where to find the length of the receiver
variable since it does not know how far down to look for it, and if it did
have some way to know how far down to look for it, It wouldn't be needed
anyway!

Any suggestions, or links on where to look for this structure?

Regards,

Jim Langston