VLOOKUP if range is based on a cell value

[mayday1]

This works, simple VLOOKUP in a second file:
=IFERROR(VLOOKUP(B4,'[DataFeed.xlsx]Personnel'!$E$3:$F$100,2),"")

But now I need I need to do the VLOOKUP when the range in the second file is different in every day's file. Today it might be $E$3:$F$100 and tomorrow it might be $E$596:$F$999.

A1 in the first file contains the name of an employee - It's a drop down so I can change the name to the person I need data for. In the second file, Column A contains rows with the names of all employees (in alphabetical order). The other columns contain data I want my VLOOKUP to get data from.

So if A1 in the first file contains the name Bob, and Bob appears in the second file in rows 53 through 323, I need my VLOOKUP in the second file to use a range of $E$53:$F$323.
But then if I change A1 in my first file to Joe, and Joe appears in the second file in row 1233 through 1400, I need my VLOOKUP in the second file to use a range of $E$1233:$F$1400.

Possible? I can't use VBA on this one - needs to be a formula.

 

[Gerald Higgins]

Is there any relationship between A1 and B4 ?
Is the value in A1 also shown in E3:F1400?

 

[mayday1]

Is there any relationship between A1 and B4 ?
In the first file, the one where I need to do the VLOOKUP, Cell A1, and only that cell, contains the name of an employee. Column B is time of day.

Is the value in A1 also shown in E3:F1400?
In the other file, Column A contains the employees names. Column E contains time of day - same as Column B in the first file. So the name isn't in the range E3:F1400 but I could make the range A3:F1400, or whatever the relevant rows are, and include the name.

A key point maybe. The first file's Column B shows all possible times by minute from 7AM through 6PM. The second file contains rows only for times when an event happened.
So the first file has
07:00
07:01
07:02
07:03
etc.

And the second file might have only rows for
07:01
07:03
07:09
etc