using excell for material selection possibly a logic problem

Welcome to the Forum Paul!

Do you have an Excel file to show what you have to start with? Let me restate what I think you mean.

You have a list of materials. Each material has an operating temperature range, given by lower and upper limits.

You want to be able to enter a target temperature range and then highlight any materials having operating limits that include the target temperature range. I interpret this to mean that the highlighted material must have an operating range that includes the entire target range. For example:

target range: -10 to 100
Material 1: -20 to 50 (fail)
Material 2: -30 to 110 (pass)
Material 3: 20 to 120 (fail)

If this is not correct, then please be more specific about the criteria for which materials you want to highlight.

Once the requirements are clear, this isn't a difficult problem to solve in Excel.