If its post 1911, then try FreeBMD.
Fill in the Mothers maiden name and leave everything else blank, specify the county as Lancs (OR even better, the district as Liverpool and possibly West Derby) and a year.
hit enter and as long as its not a really common surname , you should be able to see results.
IF its a really common surname then you may get a message saying that search would take too long or too many results to display so you may have to do it quarter by quarter for each year.
You can download the results into a csv file which will, if you use them, paste into a spreadsheet. Sounds like a really long job if there are lots with that MMN, but if you are desperate it may pay off.
and thank you, I didn't know you could search FreeBMD with just a MMN, but just tried it with a known MMN name and year/ district and it worked nicely. I've learned something new!
Boo