Looking for Guidance on Creating VBA to Grab Data from a MasterLookup Excel File

I am looking for a way to have access to a MasterLookup tab every time I open a spreadsheet, but would not be in a template.
It shouldn't be a link, since the file location could change.
There would be one tab in the MasterLookup tab with the A column in alphabetical order and one or more additional columns.
I would use Vlookup on a value in the new spreadsheet and bring back a value in the MasterLookup.
I would like the user defined function in the following situation to work something like the following:
In new spreadsheet, A2 is US.AK.AN. The command in B2 would be GetFromMaster(A2,2) and would return 27129 (see below)
In MasterLookup:
HASC 'FIPS
US.AK.AE '31011
US.AK.AN '27129
US.AK.AW '51650
US.AK.BE '55135
US.AK.BR '54081
US.AK.DE '17031
US.AK.DI '36049

"any spreadsheet in any workbook"