i want to input data into a range from a simple input location
 

From a front end - data input page i would like to make entries on a chart
withing the same file but in a different tab
Tab A would have the chart 48X48

The input sheet would be:
Example
"Y" _____ 17
"X" _____ 21

input value 30 Press enter to execute

From this the location of Y and X would be determined and a value of 30
would be placed in that location on the chart. in Tab A of the worksheet.