We need to see more of the programming to know if any part of your rslvsp() call is valid. However, if you just want a pointer for your user space, use the Retrieve Pointer to User Space (QUSPTRUS) API. — Tom

With QUSPTRUS function my program correctly return a pointer to my user space, but no matter if I change to _Program I obtain a null pointer with rslvsp even if the object is in there, we use the rslvsp due to performance reasons.The call for rslvsp is just: _SYSPTR sysP = rslvsp(_Usrspc,”USRSPC01″, “QTEMP”, _AUTH_ALL) ;
Can you explain me a little bit about that context machine ?  ( because is the only clue that I have ) 

First, do you have evidence that using QUSPTRUS causes any significant delay? Next, you say this:
 
Documentation for rslvsp points: “A null pointer value means the object was found in a machine context.”
 
But as far as I know, that is only in the MI rslvsp documentation and you are using the rslvsp() MI library procedure in C. Those are not the same. The rslvsp() MI library procedure has no such statement.
 
A null pointer might be returned from rslvsp() for a number of reasons, but there’s no way to know what that might mean without seeing more of your program. Especially, how are you handling errors?
 
Tom

My error, I thought that the cast between pointers was good and clear, but it is  when I do the cast when is returning NULL , it is weird,  when I call the program from another remote programs it returns NULL but if I call into an interactive session the pointer is correct.   I guess it is not the way to manage the system pointer 

static char * pointer = NULL ; f() {
#pragma exception_handler(errorLabel,0,0,_C2_ALL,_CTLA_HANDLE)
pointer = (char *)((void *)rslvsp(_Usrspc,”USRSPC01″, “QTEMP”, _AUTH_ALL) );
#pragma disable_handler
errorLabel:
…
}

I tested the splitting the cast and the char pointer has a valid pointer :   
static char * pointer = NULL ;
{
#pragma exception_handler(errorLabel,0,0,_C2_ALL,_CTLA_HANDLE)
void * a = (void *)rslvsp(_Usrspc,”USRSPC01″, “QTEMP”, _AUTH_ALL) ;
pointer = (char *) a;
#pragma disable_handler
}