Formula for SSRS - iif today display column in textbox - sharepoint

Question

Can anyone help me out? We're on-call for 1 week at a time.
I'm trying to display on the dashboard who is on-call this week.
I'm trying to write the following formula:
Display whatever is in 'Who's on Call' column if they are on-call this week.
Please help, I just cannot put my head around it.
<RSSharePointList xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<ListName>On Call Calendar</ListName>
<ViewFields>
<FieldRef Name="Title" />
<FieldRef Name="Location" />
<FieldRef Name="EventDate" />
<FieldRef Name="EndDate" />
<FieldRef Name="Description" />
<FieldRef Name="fAllDayEvent" />
<FieldRef Name="fRecurrence" />
<FieldRef Name="ParticipantsPicker" />
<FieldRef Name="Category" />
<FieldRef Name="Facilities" />
<FieldRef Name="FreeBusy" />
<FieldRef Name="Overbook" />
<FieldRef Name="Workspace0" />
<FieldRef Name="Partial_x0020_Hours" />
<FieldRef Name="Encoded_x0020_Absolute_x0020_URL" />
<FieldRef Name="Item_x0020_Type" />
<FieldRef Name="Path" />
<FieldRef Name="URL_x0020_Path" />
<FieldRef Name="Workflow_x0020_Instance_x0020_ID" />
<FieldRef Name="File_x0020_Type0" />
<FieldRef Name="_OldID" />
<FieldRef Name="LinkTitleNoMenu" />
<FieldRef Name="LinkTitle" />
<FieldRef Name="Whos_on_Call" />
<FieldRef Name="ID" />
<FieldRef Name="ContentType" />
<FieldRef Name="Modified" />
<FieldRef Name="Created" />
<FieldRef Name="Author" />
<FieldRef Name="Editor" />
<FieldRef Name="_UIVersionString" />
<FieldRef Name="Attachments" />
<FieldRef Name="Edit" />
<FieldRef Name="DocIcon" />
<FieldRef Name="ItemChildCount" />
<FieldRef Name="FolderChildCount" />
<FieldRef Name="AppAuthor" />
<FieldRef Name="AppEditor" />
</ViewFields>
</RSSharePointList>'