Can we use IDOC_INPUT_<Message type> for creating and changing the document

Hi,

I have a requirement to create or change the requisition data.

Can I use IDOC_INPUT_PREQCR01 function module for both the purpose.

OR shall I go for custom function module by using BAPI function modules to create or change the data.

Please help me in this regarding.

Answers will be rewarded.

Thank you.

Eswar