replacing values in linked formulas

Hi,
Could you please help me to replace the fields "Brisbane" and "BRS" with "Darwin" and "DAR" in the following formula:
"=VLOOKUP($A2697,'B:\Bud_FY11\LI_UWClaims\Brisbane\Engineering\[LI_Bud Model_FY11_BRS_ENG_CTL_ALL_NS.xls]Proj_P&L'!$A$22:$BL$102,N$3,0).

I tried to select a range of sells and replace through "find/replace" menu, however the source files are located on different drive and it doesn't work ("Update values" window pops up and kind of gets stuck).
I was thinking may be there is a way to convert formulas into text (how do I do that?) , do "find / replace", and then convert them back into formulas. Or, may be, there is the other way.
could you please help as I need to prepare huge budget upload worksheets for each state, and the file names s/s is linked to are same, just differ by state names.

Thanks a lot,
Tania