[AccessD] Excel Vlookup() question

I'm working on an Excel file created by someone else and I have to change it
to do new things, including talk to a new lookup file rather than the old
one. The following formula works:

"VLOOKUP(A7,'s:\Lgroup\Fundacct\Excel\MKT&SHS\DAILY\2007\Jun 07\[062907.xls
]R136NAVSUM'!$E$10:$I$250,4,FALSE)"

but when I change it to

"=VLOOKUP(A7,'G:\Fundacct\Excel\2007\June 2007\[Pricing 062907.xls
]TMLC'!$B$1:$H$250,4,FALSE)"


I get the N/A error. So I tried the second formula in the debug window (with
a question mark and no equals) and I get "Compile error. Expected
expression."

In the above, R136NAVSUM and TMLC are named worksheets.

I think I understand the arguments Vlookup wants (target, table_range,
relative column, nearest), so I must be doing something wrong, but I
patterned mine on the first one, and it works. The workbook referred to in
the second formula is definitely there; in fact I have it open right now as
I work on this problem.

What am I doing wrong?

TIA,
Arthur