I googled ovl files, and i came up with dos based windows overlay files, or a saved file from Railroad tycoon..neither of which seem to be database related.
can you explain what it is you need? if some program you have expects files in a specific format, maybe you could tell us the name of the program, instead of a possible extention? you might have to export to a format that both programs can use, whther CSV or watever.
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