Coding in VLOOKUP function
 

I am trying to use a VLOOKUP function within a macro. The
code I am currently attempting to use is:
VLOOKUP(RC3,'LMon & " CF"'!R8C3:R260C27,'LMon & " CF"'!R[4]
C[11],0)

where LMon is a defined variable that holds name of the
previous month. For example "Dec CF" is one of the sheets
in my workbook.

With the syntax above I am getting a Compile Error. Can
someone tell me how this shuld be correctly written.

TIA,
JC