Nikki,
it would depend on your data layout... what column contains the Company names? If i have names starting in A2 down to A100 and my next col is each companies account number, contact name, etc. my range would be A2:D100. the key with the vlookup is that the first part of your lookup range MUST be where the lookup value should be. meaning, if im looking for someones name, i specify A1:C10 as my range but Col A contains phone numbers, it will never find the name you are looking for (obviously!)
i see an issue with the formula you posted... 1) too many "("'s ..could be a copy/paste error but either way it shouldnt cause the formula to error. 2) "NO" should not be in this function. there are only 4 arguments/parts; the LookupValue ("ODE"&*),LookUpRange (a278:b316), ColumnNo (this represents which column you want to get the data from), and True/False. (True= approx it match & False=Exact match). Since your LookupRange consists of Col A and Col B, you would put 1 for your ColumnNo if you want the content in ColA returnee or use 2 for col. B.
if your other arguments are accurate it should be:
=VLOOKUP("ODE"&*,Lookup!A278:B316,2,True)
if you need me better explain anthing i just rambled on about, let me know!