Set format of rich text field

[silverspr]

I have a report with a rich text field ([testg]) showing groups of tests e.g. "cbc, ethanol, phos". I want to change the font color of test items if they are stored in a table (tblHighlight). To do this, I am trying to create a function that loops through the test items on the report and if the test item is found in tblHighlight, replaces the test item in red font in the report. I am having trouble with the syntax of the line of code in "blue" see below:

On the format event of the report, I have:

Public Function WHlight(TestG As String)
Dim dbs As Database
Dim rs As Recordset

Dim Idx As Long

Set dbs = CurrentDb
Set rs = dbs.OpenRecordset("tblHighlight", dbOpenDynaset)

rs.MoveLast
rs.MoveFirst

Idx = 1
For Idx = 1 To rs.RecordCount
'Debug.Print rs!htest
If InStr(TestG, rs!htest) > 0 Then
TestG = Replace(TestG, rs!htest, "<font color=""red"">rs!htest</font>")
WHlight = TestG
End If
rs.MoveNext
Next Idx
rs.Close


Set dbs = Nothing
End Function

thanks for your help in advance