This is from the variables.h file
#define ThisPerformance (g->w)
#define DrawDownMax g->w.vDrawDown
#define MAE g->w.vEquityDown
#define MarginMax g->w.vMarginMax
#define RiskMax g->w.vRiskMax
#define SpreadCost g->w.vSpreadCost
#define SlippageCost (g->w.vSlippageWin+g->w.vSlippageLoss)
#define RollCost g->w.vRollCost
#define CommissionCost g->w.vCommissionCost
#define ReturnMean g->w.vMean
#define ReturnStdDev g->w.vStdDev
#define Ulcer g->w.vUlcer
#define R2 g->w.vR2
#define DrawDownBars g->w.numDrawDownBars
#define DrawDownBarsMax g->w.numDrawDownMax
#define LossStreakMax g->w.numLossStreakMax
#define NumOpenMax g->w.numTradesMax
#define InMarketBars g->w.numMarketBars
#define InMarketSum g->w.numMarketTotal
My understanding is that you use for example ThisPerformance.vR2 to get the R2