I wrote the formula to a cookie and then used a page that looks like this to be the final driver of the report.
Hope it helps.
<%
Dim ObjectFactory, HTMLViewer
Set ObjectFactory = CreateObject("CrystalReports.ObjectFactory.2"

Set HTMLViewer =ObjectFactory.CreateObject("CrystalReports.CrystalReportViewer"
Dim clientDoc
Set clientDoc = ObjectFactory.CreateObject("CrystalReports.ReportClientDocument"

clientDoc.ReportAppServer = "SERVERNAME"
clientDoc.Open "REPORT.rpt"
'==================================================================
' WORKING WITH FREE EDITING RECORD FILTERS
' - Retrieve the filter object through the DataDefController
' - Set the text of the Record Filter through the FreeEditingText property
' - Modify the record filter through the Record Filter Controller
'==================================================================
Dim filter
Dim formula
formula=request.cookies("studentinfo"

("formula"
' Retrieve the filter object through the DataDefController
Set filter = clientDoc.DataDefController.DataDefinition.RecordFilter
' Set the text of the Record Filter through the FreeEditingText property
filter.FreeEditingText = formula
' Modify the record filter through the Record Filter Controller
clientDoc.DataDefController.RecordFilterController.modify filter
With HTMLViewer
.IsOwnPage = true
.IsOwnForm = true
.IsDisplayGroupTree =true
.IsBestFitPage = true
.ReportSource = clientdoc.reportsource
End With
call HTMLViewer.ProcessHttpRequest(Request, Response,session)
%>