Thx, this helps very much, I'll try it out immediately. After having passed the pointer to the C-struct to Perl space I think to use Convert::Binary::C as suggested by the 2nd comment on my question.
Is it faster to fiddle around the C struct in C and use the Perl stack or give just a pointer to Perl and fiddle around the C-struct in Perl ? This needs more investigaton into the Convert::Binary::C. Any advice onto this would be highly appreciated.