Using variables in the Range function

Hello, so here's my code so far the last line is the one that's giving me trouble. basically lets say endMatrix = the cell "K11" Then I want have "Range("A1:K11").PasteSpecial" -- I'm having trouble with using the variable "endMatrix" in the function though it has to be something with my Syntax because I've never quite gotten the hang of using variables in functions.

Should be an easy fix? Thanks for the help!

Sub testStuff()
Dim endMatrix As Range

Range("A1").Select
ActiveCell.Value = "test"
Set endMatrix = ActiveCell.Offset(10, 10)
ActiveCell.Copy
Range("A1:" & endMatrix&).PasteSpecial

End Sub

Worked perfectly! Thanks!