How to find and change text in PDF document using QTP UFT automation VBscript

Hi Colleagues,

I need some help from you.
I need to write test case in VBscript for QTP / UFT (12.51)

QTP should launch Adobe Acrobat Pro 9, 10, 11 (all available on testing machines) open existing PDF file from testing folder. Find some text in the PDF document. Select this text and replace with another text. Save changes. Close file. Close Acrobat. Everything looks very simple but I spent 2 days without results. And didn’t find any working code solution.
findText() method didn’t find the text and I can’t proceed

Thank you in advance for any help and advice.