Look up Single list value & Return multiple corresponding values While Adding New Rows

Hello,

I'm looking for a way to have excel look up one value (from a list) and return multiple corresponding values while adding new rows.

For example, using the following data:
In Sheet 1 in column A

A1:GL01
A2:GL02
A3:GL02
A4:GL03
A5:GL04
A6:GL04

In Sheet 2 in column A And B

A1:GL01 B1: aaa
A2:GL01 B2: aaa
A3:GL01 B3: aaa
A4:GL01 B4: aaa
A5:GL02 B5: bbb
A6:GL02 B6: bbb
A7:GL03 B7: ccc
A8:GL03 B8: ccc

I want to match the value in sheet 1 Column A into sheet 2 Column A
And bring the values into sheet 1 column B from the Sheet 2 column B

FOR EXAMPLE:
In Sheet 1
Column A Column B
A1:GL01 B1: aaa
A2:GL01 B2: aaa
A3:GL01 B3: aaa
A4:GL01 B4: aaa
A5:GL02 B5: bbb
A6:GL02 B6: bbb
A7:GL03 B7: ccc
A8:GL03 B8: ccc

Any formula or Macro will work for me.
I am in hurry as i need to solve this in next 20 hours.
Any thoughts, suggestions?

Thank you!

Maybe:

=VLOOKUP(A1,Sheet2!$A$1:$B$90,2,FALSE)

No i want a formula that can add rows into sheet 1 if in vlookup resulting values are more than one.
Means if criteria is true than bring the values into sheet1 column B from sheet 2 column B while adding new rows.