Nested/Conditional IF statement

I have a row of cells that each do a wildcard search on a text string to deliver a 1 result if true. the formula is as follows;

=IF(ISNUMBER(SEARCH("*A40",B52)), 1, "")

The problem I have is that 2 other cell formulas clash which are;

=IF(ISNUMBER(SEARCH("*A408",B52)), 1, "")
=IF(ISNUMBER(SEARCH("*A4087",B52)), 1, "")

All formulas when finding A4087 return a 1 when I only want it in the last
The first 2 formulas return a 1 when finding A408 and I only want it in the second.

I have tried using a space i.e. "*A40 " & "*A408 " but then I lose data if words run into the string i.e. A40silver would not pick up the text at all.

My proposed solution is to do a conditional if statement i.e. for the A40 search, if A40 is found check if there is a "" in the other 2 corresponding cells before returning a 1. But I can't get the if statement to work. I am sure it should be possible and fairly straight forward but am really struggling to find the written solution !!!

Are there any takers to help me out please. I can happily mock up something to explain better if required. Oh...and I want to stick with formula and not use VBA on this.

regards

Simon