CGI-RPG Parameters with different sizes

Hi group!

I have a Program A that is sending three parameters to a Program B:

Field 1 = 5 char long, value is '1'
Field 2 = 15 char long, value is '1364647'
Field 3 = 7 char long, value is M111110

When I display my values on program B, I am only able to receive them using a
data structure like this:

DEnvData          DS
D   StartAtLoc                        Like(RQGDML)  (is 5 long)
D   StartAtItem                       Like(RQGDGR)  (is 15 long)
D   StartAtOrd                   7

However, while debugging Program B, EnvData contains the following value:
EVAL EnvData
STARTATLOC OF ENVDATA = '21307'
STARTATITEM OF ENVDATA = '459M111110     '
STARTATORD OF ENVDATA = '       '

How I can determine the right positions of the data?  Is the data structure
poorly defined?

TIA

Peter Vidal
Pall Aeropower Corp.
Programmer Analyst