Ya resolví al parecer, les dejo el código por si a alguien le es de ayuda, un amigo me explicó por teléfono que existen sub select y tal, lo busqué y me funcionaron.
Código SQL
[-]SELECT TPROD,
SUM(CASE WHEN TTDTE LIKE '%' + @TTDTE + '01%' AND TPROD LIKE 'Q%' THEN (T1 + T2 + T3) * - 1 ELSE 0 END)
/(SELECT SUM(T1+T2+T3)/1000
FROM BPCS_TRANS_ITH_2
WHERE (TTDTE LIKE '%' + @TTDTE + '01%') AND (THWRKC LIKE '431101') AND TTYPE = 'R') AS Enero,
SUM(CASE WHEN TTDTE LIKE '%' + @TTDTE + '02%' AND TPROD LIKE 'Q%' THEN (T1 + T2 + T3) * - 1 ELSE 0 END)
/(SELECT SUM(T1+T2+T3)/1000
FROM BPCS_TRANS_ITH_2
WHERE (TTDTE LIKE '%' + @TTDTE + '02%') AND (THWRKC LIKE '431101') AND TTYPE = 'R') AS Febrero,
SUM(CASE WHEN TTDTE LIKE '%' + @TTDTE + '03%' AND TPROD LIKE 'Q%' THEN (T1 + T2 + T3) * - 1 ELSE 0 END)
/(SELECT SUM(T1+T2+T3)/1000
FROM BPCS_TRANS_ITH_2
WHERE (TTDTE LIKE '%' + @TTDTE + '03%') AND (THWRKC LIKE '431101') AND TTYPE = 'R') AS Marzo,
SUM(CASE WHEN TTDTE LIKE '%' + @TTDTE + '04%' AND TPROD LIKE 'Q%' THEN (T1 + T2 + T3) * - 1 ELSE 0 END)
/(SELECT SUM(T1+T2+T3)/1000
FROM BPCS_TRANS_ITH_2
WHERE (TTDTE LIKE '%' + @TTDTE + '04%') AND (THWRKC LIKE '431101') AND TTYPE = 'R') AS Abril,
SUM(CASE WHEN TTDTE LIKE '%' + @TTDTE + '05%' AND TPROD LIKE 'Q%' THEN (T1 + T2 + T3) * - 1 ELSE 0 END)
/(SELECT SUM(T1+T2+T3)/1000
FROM BPCS_TRANS_ITH_2
WHERE (TTDTE LIKE '%' + @TTDTE + '05%') AND (THWRKC LIKE '431101') AND TTYPE = 'R') AS Mayo,
SUM(CASE WHEN TTDTE LIKE '%' + @TTDTE + '06%' AND TPROD LIKE 'Q%' THEN (T1 + T2 + T3) * - 1 ELSE 0 END)
/(SELECT SUM(T1+T2+T3)/1000
FROM BPCS_TRANS_ITH_2
WHERE (TTDTE LIKE '%' + @TTDTE + '06%') AND (THWRKC LIKE '431101') AND TTYPE = 'R') AS Junio,
SUM(CASE WHEN TTDTE LIKE '%' + @TTDTE + '07%' AND TPROD LIKE 'Q%' THEN (T1 + T2 + T3) * - 1 ELSE 0 END)
/(SELECT SUM(T1+T2+T3)/1000
FROM BPCS_TRANS_ITH_2
WHERE (TTDTE LIKE '%' + @TTDTE + '07%') AND (THWRKC LIKE '431101') AND TTYPE = 'R') AS Julio,
SUM(CASE WHEN TTDTE LIKE '%' + @TTDTE + '08%' AND TPROD LIKE 'Q%' THEN (T1 + T2 + T3) * - 1 ELSE 0 END)
/(SELECT SUM(T1+T2+T3)/1000
FROM BPCS_TRANS_ITH_2
WHERE (TTDTE LIKE '%' + @TTDTE + '08%') AND (THWRKC LIKE '431101') AND TTYPE = 'R') AS Agosto,
SUM(CASE WHEN TTDTE LIKE '%' + @TTDTE + '09%' AND TPROD LIKE 'Q%' THEN (T1 + T2 + T3) * - 1 ELSE 0 END)
/(SELECT SUM(T1+T2+T3)/1000
FROM BPCS_TRANS_ITH_2
WHERE (TTDTE LIKE '%' + @TTDTE + '09%') AND (THWRKC LIKE '431101') AND TTYPE = 'R') AS Septiembre,
SUM(CASE WHEN TTDTE LIKE '%' + @TTDTE + '10%' AND TPROD LIKE 'Q%' THEN (T1 + T2 + T3) * - 1 ELSE 0 END)
/(SELECT SUM(T1+T2+T3)/1000
FROM BPCS_TRANS_ITH_2
WHERE (TTDTE LIKE '%' + @TTDTE + '10%') AND (THWRKC LIKE '431101') AND TTYPE = 'R') AS Octubre,
SUM(CASE WHEN TTDTE LIKE '%' + @TTDTE + '11%' AND TPROD LIKE 'Q%' THEN (T1 + T2 + T3) * - 1 ELSE 0 END)
/(SELECT SUM(T1+T2+T3)/1000
FROM BPCS_TRANS_ITH_2
WHERE (TTDTE LIKE '%' + @TTDTE + '11%') AND (THWRKC LIKE '431101') AND TTYPE = 'R') AS Noviembre,
SUM(CASE WHEN TTDTE LIKE '%' + @TTDTE + '12%' AND TPROD LIKE 'Q%' THEN (T1 + T2 + T3) * - 1 ELSE 0 END)
/(SELECT SUM(T1+T2+T3)/1000
FROM BPCS_TRANS_ITH_2
WHERE (TTDTE LIKE '%' + @TTDTE + '12%') AND (THWRKC LIKE '431101') AND TTYPE = 'R') AS Diciembre,
SUM(CASE WHEN TTDTE LIKE '%' + @TTDTE + '%' AND TPROD LIKE 'Q%' THEN (T1 + T2 + T3) * - 1 ELSE 0 END)
/(SELECT SUM(T1+T2+T3)/1000
FROM BPCS_TRANS_ITH_2
WHERE (TTDTE LIKE '%' + @TTDTE + '%') AND (THWRKC LIKE '431101') AND TTYPE = 'R') AS Total_Anual
FROM BPCS_TRANS_ITH_2
WHERE (TTDTE LIKE '%' + @TTDTE + '%') AND (THWRKC LIKE '431101') AND TPROD LIKE 'Q%' AND TTYPE = 'I'
GROUP BY TPROD
ORDER BY TPROD
SELECT SUM(T1+T2+T3)
FROM BPCS_TRANS_ITH_2
WHERE (TTDTE LIKE '%' + @TTDTE + '01%') AND (THWRKC LIKE '431101') AND TTYPE = 'R'