@Nived_Nambiar ,
Thank you for your response. Following are my comments:
1. Could you tell what is input source of purchase requisition values ?
Purchase requisition values can come from variety of sources including invoices from various suppliers which all come in different shape and formats and quotes, or sometimes Excel or word documents, but it has to be VAT exclusive amount.
2. Does PDF/Excel files has same structure always ?
Unfortunately, no, and more problematic thing is that depending on the ability of the data inputting person, there could be many mistakes which doesn't agree with the attached supporting documents. My job is to check the accuracy of data input which could potentially contain many inputting errors, and I'd like to automate this uninspiring job away. I need to communicate to the data inputter where the mistake is and why it is not matching with the attached supporting documents and it gets repetitive and boring.
Thank you for your help.