compare columns

[Bob]

I have two columns L3:M27636.
In column L3:L27636 I have numbers 1234, 4321 etc.
In column M3:M27636 I have either blank cells or numbers 709000.
If column L and M has a number they would match through the worksheet
for example if L4 has 1234 and M4 has 709000 then anywhere 1234 appears in
column L the corresponding cell in column M would be 709000.

I would like a formula that says if M3 is blank, look in L3:l27636, match
this to L3 and if there is a match and has data in the corresponding cell in
column M insert the number or else insert a blank.

I tried =IF(ISBLANK(M3),VLOOKUP(L3,$L$2:$M$27635,2,FALSE),M3) which didn't
work.

 

[Max]

One guess

Try this in say, N2:
=IF(L2="","",IF(M2="",VLOOKUP(L2,L3:$M$27635,2,0),""))
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