I have two workbooks; one contains a list of mtrl Lot numbers in one column
and in the next wether it was accepted or not; the other worksheet is a form
in which the end user fills out. I want to check wether the lot numbers in
the form are in the summary or not and if it was accepted or not. Once I have
this info I need to let the end user by coloring the cell with the lot number
on the form.

This is what I've got now:
Sub Test
Dim rR As Range
Dim rRM As Range
Dim dDM As Double
Dim strValue As String

Application.Workbooks.Open("M:\BodyPrep\ALL BATCH MATERIAL TESTS &
RESULTS\- RAW SUMMARY - COA's.xls", False, False).Activate

Application.Workbooks("- RAW SUMMARY - COA's.xls").Worksheets("RAW MTRL
COA's").Activate
Range("$D$2:$E$3000").Select
Set rR = Selection

Range("$D$2:$D$3000").Select
Set rRM = Selection

For x = 10 To 11
strValue = Application.ThisWorkbook.Worksheets("Data Entry").Range
("E" & x).Value
Application.Workbooks("- RAW SUMMARY - COA's.xls").Activate

dDM = Application.WorksheetFunction.Match(strValue, rRM)

If Application.WorksheetFunction.Index(rR, dDM, 3) = "VALID" Then
Application.ThisWorkbook.Range("E" & x).Interior.ColorIndex
(3)
End If
Next x
End Sub