Spreadsheet: 37917d1236020727-sum-a-range-based-on-a-starting-lookup-value-example
Sheet: Sheet1

 |  |  | Data
 | First Activity Month Code | Original Sales Rep | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | [NAME] Here
 | 73 | [NAME] | 11158.91 | 14735.01 | 15518.45 | 6566.98 | 6707.28 | 3557.56 | 5531.92 | 6066.73 | 4811.48 | 3698.33 | 2692.02 | 2891.01 | 6722 | 8939.88 | 11449.52 | 8641.94 | 5681.06 | 166610.79
 | 74 | [NAME] | 500 | 9733.99 | 15634.66 | 8886.56 | 7654.23 | 12729.79 | 7016.56 | 4154.97 | 5178.14 | 6513.7 | 3065.95 | 1606.56 | 2465.07 | 4485.3 | 4568.51 | 3607.31 | 2219.07 | 84640.18
 | 75 | [NAME] | 2926.01 | 1720.25 | 11190 | 13127.18 | 8691.68 | 7308.32 | 4781.64 | 2615.06 | 3505.82 | 7207 | 3421.83 | 2177.39 | 6936.03 | 6563.18 | 8033.15 | 7315.15 | 7605.08 | 77525.13
 | 75 | Javier | 0 | 0 | 705.52 | 878.41 | 234.36 | 159.77 | 45.56 | 41.61 | 35.98 | 34.71 | 37.3 | 23.54 | 33.88 | 18.05 | 1275.34 | 693.8 | 380.64 | 2248.690000000001
 | 75 | Kathy | 0 | 0 | 346.5 | 1301.75 | 252.75 | 33 | 303 | 270 | 899.6 | 2052.11 | 231.15 | 202.6 | 201.75 | 157.7 | 189 | 117 | 177 | 6251.91
 | 76 | [NAME] | 0 | 0 | 500 | 8742.06 | 9102.28 | 4072.38 | 2412.28 | 1728.4 | 3310.18 | 2452.92 | 946.51 | 1086.8 | 4079.57 | 4685.05 | 1828.38 | 4745.71 | 8769.38
 | 76 | Javier | 0 | 0 | 0 | 3320.99 | 1275.45 | 673.85 | 946.95 | 737.56 | 625.33 | 922.87 | 706.96 | 760.77 | 1067.51 | 296.13 | 609.19 | 424.78 | 1710.66
 | 76 | Kathy | 0 | 0 | 0 | 2909.77 | 6432.08 | 2091.34 | 1295.78 | 351 | 1667.62 | 1596.63 | 973.5 | 150 | 393.5 | 202.5 | 2662.5 | 3151.05 | 2764.18
 | 77 | [NAME] | 0 | 0 | 0 | 0 | 8757.87 | 7851.5 | 3245.98 | 5075.3 | 3190.77 | 831.51 | 2577.55 | 1654.44 | 3387.59 | 4336.3 | 5135.62 | 3044.24 | 293.14
 | 77 | Javier | 0 | 0 | 0 | 500 | 2462.62 | 2654.22 | 1012.65 | 249.46 | 882.57 | 696.46 | 685.37 | 368.66 | 552.36 | 393.93 | 309.86 | 545.17 | 1622.01
 | 77 | Kathy | 0 | 0 | 0 | 0 | 4149.82 | 3062.82 | 855.46 | 2450.36 | 2068.01 | 3720.87 | 2579.03 | 1150.5 | 2415.8 | 1437.27 | 1441.22 | 2591.07 | 3549.69
 | 77 | Sue | 0 | 0 | 0 | 0 | 42.28 | 163.19 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0
 | 78 | [NAME] | 0 | 0 | 0 | 0 | 18 | 5371.39 | 5454.6 | 7335.89 | 3053.68 | 2044.76 | 1467 | 960.28 | 581.18 | 429.56 | 584.84 | 2359.15 | 583.4
 | 78 | Javier | 0 | 0 | 0 | 0 | 500 | 1849.97 | 3132.19 | 2312.49 | 2481.91 | 884.88 | 342.22 | 141.36 | 1122.5 | 1147 | 1297.58 | 838.51 | 283.92
 | 78 | Kathy | 0 | 0 | 0 | 0 | 0 | 5810.36 | 2912.47 | 4032.54 | 3501.56 | 3527.78 | 1097.21 | 296.97 | 962.72 | 259.43 | 736.45 | 965.67 | 2779.35
 | 78 | Sue | 0 | 0 | 0 | 0 | 0 | 965.4 | 1118.7 | 830.7 | 284.4 | 140.4 | 62.1 | 0 | 0 | 0 | 0 | 0 | 0
 | 79 | [NAME] | 0 | 0 | 0 | 0 | 0 | 4.5 | 2387.57 | 2972.72 | 2161.1 | 1492.48 | 773.93 | 506.64 | 1388.86 | 661.47 | 741.18 | 518.32 | 156.95
 | 79 | Javier | 0 | 0 | 0 | 0 | 0 | 0 | 2057.48 | 2285.15 | 2852.51 | 145.95 | 418.88 | 572.2 | 528.77 | 125.25 | 120.15 | 173 | 686.9
 | 79 | Kathy | 0 | 0 | 0 | 0 | 0 | 3 | 4552.84 | 3308.83 | 6384.08 | 3574.02 | 2088.25 | 552.65 | 331.5 | 1608.16 | 1708.32 | 2294.8 | 1633.59
 | 80 | [NAME] | 0 | 0 | 0 | 0 | 0 | 126 | 423 | 7677.65 | 9990.76 | 8955.15 | 2286.47 | 1885.63 | 6214.46 | 2833.72 | 4042.4 | 1798.95 | 2456.63
 | 80 | Javier | 0 | 0 | 0 | 0 | 0 | 0 | 18 | 2198.09 | 3256.68 | 1476.74 | 63.24 | 154.33 | 832.15 | 985.76 | 502.49 | 1249.74 | 658.14
 | 80 | Kathy | 0 | 0 | 0 | 0 | 0 | 13.5 | 13.5 | 6528.49 | 4489.51 | 2219.18 | 1094.98 | 912.55 | 856.25 | 2085.5 | 463.61 | 466.5 | 859.79
 | 80 | [NAME] | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 150 | 39 | 36 | 0 | 0 | 0 | 0 | 0 | 0 | 0
 | 80 | Sue | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 549 | 1674 | 72 | 30 | 0 | 0 | 1020 | 1122 | 6 | 1512
 | 81 | [NAME] | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 5935.81 | 8135.21 | 1140.47 | 941.82 | 4464.07 | 5614.82 | 6116.47 | 2539.24 | 1882.9
 | 81 | Javier | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 3499.62 | 3040.78 | 456.69 | 636.3 | 265.55 | 196.38 | 413.49 | 358.06 | 101.62
 | 81 | Kathy | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 5165.25 | 4129.3 | 3374.53 | 814.43 | 3787.14 | 2074.87 | 2620.8 | 1497.78 | 1745.87
 | 81 | [NAME] | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 526.05 | 428.56 | 308.4 | -13.1 | 256.59 | 836.78 | 731.65 | 336.3 | 368.85
 | 81 | Sue | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 3805.99 | 3431.19 | 1625.54 | 1448.6 | 1856.95 | 4499.23 | 4752.32 | 2967.04 | 1684.11
 | 82 | [NAME] | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 5992.54 | 2535.64 | 2214.68 | 4496.65 | 2822.26 | 1735.08 | 402.82 | 571.19