I need a little help on whether this should be done with a Macro or an IF statement.

On the first tab, there is a field that the user inputs, and then i need to go to the second tab and if the field is in between the range of the column C and D, then i need to return Column A and E back to the first tab. But if it is not in the range, it needs to go down to the next line, and the next line until the range is met. Any ideas? I need a little help.

THANKS!