Here's how I might handle this: Number of even rolls out of [[ ?{Stat|Force, @{Force} [Force]|Endurance, @{Endurance} [Endurance]} ]]**d6**:
/r ?{Stat} - (1d6%2 + [[ {?{Stat} + d0}>2 ]]d6%2 + [[ {?{Stat} + d0}>3 ]]d6%2 + [[ {?{Stat} + d0}>4 ]]d6%2) (If a stat can go above 4, you'll want to adjust the macro accordingly, i.e. by adding + [[ {?{Stat} + d0}>5 ]]d6%2, etc.) [[ {?{Stat} + d0}>2 ]] equals 1 if ?{Stat} ≥ 2. Otherwise, it equals 0. The above's a bit advanced, so, of course, feel free to ask questions.