Help with finding text strings in other text strings.

Hi,
I am confident someone can help me solve the issue that is wrecking my head at the moment.

I would like to be able to look for a piece of a text string which is in a specific cell in one workbook in a list which is held in another workbook.

E.g. the following text "ESB" is held in cell A1 in Workbook A. I know that in the list in Workbook B there is "ESB International". I want to create a formula that looks for the text held in Workbook A, cell A1, in the list in Workbook B and returns the value "True" if it is there and "False" if it is not.

I'm scrambling my brain with FIND MATCH VLOOKUP LOOKUP functions but have a feeling I am on the wrong track... really is it that hard to ask a formula in excel to take the string in one cell and look up in a list a SIMILAR but NOT exact match??

I sure hope I am being clear with my request here and would be very grateful if anyone could help me out.

Many thanks in advance
G