I have a large matrix of values, left column goes from 40 to 192 by 2's and
the header row goes from 5 to 50 by 1's, but for my question I will use a
small matrix. The table value is just the row header multiplied by the column
header of that cell.

5 6 7 8 9 10 11
40 200 240 280 320 360 400 440
42 210 252 294 336 378 420 462
44 220 264 308 352 396 440 484
46 230 276 322 368 414 460
48 240 288 336 384 432 480
50 250 300 350 400 450 500
52 260 312 364 416 468
54 270 324 378 432 486
56 280 336 392 448
58 290 348 406 464

From week to week I have a different value to look for in the first column.
Say this week that I need to look in the row with 52 in the left column. I
need a formula, or macro, that looks for the value closest to but not greater
than 500 and then returns the column header value of that cell. In this case
it would be 9. Next week I might need to look for 58 and I need to return 8.
The criteria of 500 could change so I need that to reference from a cell with
500 in it.

I thought of a GETPIVOTDATA function but I don't think that's going to do
what I need. I don't have a good grasp of all of the advanced LOOKUP
functions to just go right to it.

Any help would be appreciated.

Don M.