Need Help Finding Text in a "rectangle boxes"

Dear All,
Need your help, if possible please. I am a new user using VBA.

I have large ammounts of text stored in “rectangle” boxes across my spreadsheets, as I have copied and pasted flowcharts created in another application. I am trying to use (Ctrl+F) to find text in the flowchart, however I noticed that the normal Find option doesn't work. Is there any way to perform such a search? I also tried to use the VBA code below and it could not work out as well? Any help on this is much appreciated.

Sub Findtext()
'Updateby20140603
Dim xWs As Worksheet
Dim shp As Shape
Dim xFindStr As String
Dim xReplace As String
xFindStr = Application.InputBox("Find:", xTitleId, "", Type:=2)
xReplace = Application.InputBox("Replace:", xTitleId, "", Type:=2)
Set xWs = Application.ActiveSheet
On Error Resume Next
For Each shp In xWs.Shapes
xValue = shp.TextFrame.Characters.Text
shp.TextFrame.Characters.Text = VBA.Replace(xValue, xFindStr, xReplace, 1)
Next
End Sub

could you provide an example worksheet so that we can see what type your rectangle boxes are exactly?

Hello LordLoki,
thanks for trying to assist me on this issue. Attached please find an example of the flowcharts, i am trying to find text in the rectangular boxes.I struggled a bit to get the file attached. Hopefully, I managed to get it through:) . Thanks again for your support.

Thank you very much for your support indeed. I see this as a very helpful material. Just one thing, may I ask you what if, I only wanted to find the “names of people” instead of “positions”? Please refer to the boxes shaded in green for your reference. To make it shorter, I would not need to make the use of the REPLACE function. Please accept my apologies in advance if I am asking too much.