Reports :: Passing Variable To Report Record Source?

I have a subroutine that successfully builds a SQL statement "strSQL", which is a public variable.

Using msgbox, I can read that the value is correct -
SELECT * from tblIncidents WHERE [Nature] = 'Hover';

(The select statement may be complex, e.g. [Nature] = 'hover' AND [COLOUR]= 'Blue' AND [GRADE] = 'High')

I want to pass the variable strSql to my report rptIncident in the following command:

Private Sub CmdPrintReport_Click()
If Right(strsql, 1) <> "'" Then 'check if statement was built
Else
strsql = strsql & ";" 'add trailing ; to statement
MsgBox strsql
DoCmd.OpenReport "tblincidents", acViewNormal, , strsql
End If
End Sub

I get a flashing error, then runtime error 3075 - |1 in query expression '|2'.