Get number value from TestStand Station globals

Hello,

I want to get the value of few variables (type number) fro the Station Globals of TestStand. 

I have CVI 2013 / WIN7

I did this :

TSerrChk(TS_SeqContextGetStationGlobals (rSequenceContext, NULL, &rStationGlobalsLocalsObject));    

//Chech if C1_CTR_LSR_POW_A is liseted on TestStand
		TSerrChk(TS_PropertyExists (rStationGlobalsLocalsObject, &errorInfo, "C1_CTR_LSR_POW_A", 0, &iExists));
		if(iExists == -1)
		{
			TSerrChk(TS_PropertyGetValNumber (rStationGlobalsLocalsObject, &errorInfo, "C1_CTR_LSR_POW_A", 0, &gPowA));
		}
		else  //Variable doesn't exist
		{
			sprintf(&pcReportTxt[strlen(pcReportTxt)], "Var not found : %s\n", "C1_CTR_LSR_POW_A");
			*piStepResult = FAIL;
			error = -1;
			goto Error;
		}

The problem is that I get always Zero in my variable gPowA.

Any idea please ?