Hi,
You can use transaction code MIR6 for the same.
Please follow the process as given below :
1. Create an document using transaction code MIR7.
2. Go to transaction code MIR6.
3. Enter Fiscal Year
4. Enter Company Code.
5. In Entry Type - Select - Held / Parked
6. Select Invoice Status
7. Click on Execute
8. You will see list of documents Parked.
9. Select the document you want to post.
10. Click on Pencil.
11. Save document.
In case of any doubts / queries / clarifications please feel free to revert.
Regards,
Tejas