[FrankP]

UPDATE:

I did it now by using:

<vb:if condition="(THIS_SCRIPT == showthread) AND (in_array($post['postcount'], array(5,20,35,50,65,80,95,110,125,140,155,170,185, 200,215,230,245,260,275,290,30 5,320,335,350,365,380,395,410,425,440,455,470,485, 500,515,530,545,560,575,590,60 5,620,635,650,665,680,695,710,725,740,755,770,785, 800,815,830,845,860,875,890,90 5,920,935,950,965,980,995,1010,1025,1040,1055,1070 ,1085,1100,1115,1130,1145,1160 ,1175,1190,1205,1220,1235,1250,1265,1280,1295,1310 ,1325,1340,1355,1370,1385,1400 ,1415,1430,1445,1460,1475,1490,1505,1520,1535,1550 ,1565,1580,1595,1610,1625,1640 ,1655,1670,1685,1700,1715,1730,1745,1760,1775,1790 ,1805,1820,1835,1850,1865,1880 ,1895,1910,1925,1940,1955,1970,1985,2000,2015,2030 ,2045,2060,2075,2090,2105,2120 ,2135,2150,2165,2180,2195,2210,2225,2240,2255,2270 ,2285,2300,2315,2330,2345,2360 ,2375,2390,2405,2420,2435,2450,2465,2480,2495,2510 ,2525,2540,2555,2570,2585,2600 ,2615,2630,2645,2660,2675,2690,2705,2720,2735,2750 ,2765,2780,2795,2810,2825,2840 ,2855,2870,2885,2900,2915,2930,2945,2960,2975,2990 ,3005,3020,3035,3050,3065,3080 ,3095,3110,3125,3140,3155,3170,3185,3200,3215,3230 ,3245,3260,3275,3290,3305,3320 ,3335,3350,3365,3380,3395,3410,3425,3440,3455,3470 ,3485,3500,3515,3530,3545,3560 ,3575,3590,3605,3620,3635,3650,3665,3680,3695,3710 ,3725,3740)))">
<div class="thread_controls">
<div style="width: 100%; text-align: center">
<!--@vbbanners:2@-->
</div>
</div>
</vb:if>
<vb:if condition="(THIS_SCRIPT == showthread) AND (in_array($post['postcount'], array(10,25,40,55,70,85,100,115,130,145,160,175,19 0,205,220,235,250,265,280,295, 310,325,340,355,370,385,400,415,430,445,460,475,49 0,505,520,535,550,565,580,595, 610,625,640,655,670,685,700,715,730,745,760,775,79 0,805,820,835,850,865,880,895, 910,925,940,955,970,985,1000,1015,1030,1045,1060,1 075,1090,1105,1120,1135,1150,1 165,1180,1195,1210,1225,1240,1255,1270,1285,1300,1 315,1330,1345,1360,1375,1390,1 405,1420,1435,1450,1465,1480,1495,1510,1525,1540,1 555,1570,1585,1600,1615,1630,1 645,1660,1675,1690,1705,1720,1735,1750,1765,1780,1 795,1810,1825,1840,1855,1870,1 885,1900,1915,1930,1945,1960,1975,1990,2005,2020,2 035,2050,2065,2080,2095,2110,2 125,2140,2155,2170,2185,2200,2215,2230,2245,2260,2 275,2290,2305,2320,2335,2350,2 365,2380,2395,2410,2425,2440,2455,2470,2485,2500,2 515,2530,2545,2560,2575,2590,2 605,2620,2635,2650,2665,2680,2695,2710,2725,2740,2 755,2770,2785,2800,2815,2830,2 845,2860,2875,2890,2905,2920,2935,2950,2965,2980,2 995,3010,3025,3040,3055,3070,3 085,3100,3115,3130,3145,3160,3175,3190,3205,3220,3 235,3250,3265,3280,3295,3310,3 325,3340,3355,3370,3385,3400,3415,3430,3445,3460,3 475,3490,3505,3520,3535,3550,3 565,3580,3595,3610,3625,3640,3655,3670,3685,3700,3 715,3730,3745)))">
<div class="thread_controls">
<div style="width: 100%; text-align: center">
<!--@vbbanners:3@-->
</div>
</div>
</vb:if>

This way I'm prepared for threads with up to 250 pages, but this is much more dirty than quick :-)