I have a to find serial numbers of multiple types of equipment from one work
book that appear in another workbook. The serial numbers range from 4 digits
to 15 digits or more.

The major problem for me is, in the spreadsheet I am looking in, often there
are multiple serial numbers in one cell separated by a symbol or symbols.
These symbols are rarely the same. VLOOKUP is no use in this instance.

I realize I could just use the find button and type in each serial number
but with 20K lines it would take an eternity. (my issue now)

I need to identify the matches somehow either by changing a font or placing
a Y in a column something that would do this without going line by line.

Any help would be appreciated.