MI-L how can I get coordinates of hg_bounding_box (SpatialWare)

[קליימן יבגני]

Hello,
I try to get MBR (or MER) of all geometries in a table. Following to UserGuide of 
Spatialware I write
 
sp_spatial_query 
'select hg_bounding_box(sw_geometry)
from mytestcon'
 
and it works but I get some binary object. Now I would like to know coordinates of 
this object. How? I tried
 
sp_spatial_query 
'select HG_GetString(hg_bounding_box(sw_geometry))
from mytestcon'
 
but it is finished by a message:
SW-70901: Syntax error detected at line 471: syntax error at 'hg_bounding_box'.
 
Waiting for help
Evgeny