Is there a way to access the ProjectWise API from Excel?

You should be able to access the ProjectWise APIs using VBA as you would any other native code based API, but unfortunately, I don't have any experience doing so with VBA.  Perhaps someone else in the community might be able to provide some advice.

Looking at your description of what you are attempting to do, i.e. upload files, create documents codes, from data in a spreadsheet, have you considered using PowerShell to accomplish this?

PWPS_DAB has Cmdlets that will do the tasks you mention, and of course Microsoft provides PowerShell Cmdlets to manipulate Excel.  Perhaps that approach might be a consideration for a solution to your requirements?

You should be able to access the ProjectWise APIs using VBA as you would any other native code based API, but unfortunately, I don't have any experience doing so with VBA.  Perhaps someone else in the community might be able to provide some advice.

Looking at your description of what you are attempting to do, i.e. upload files, create documents codes, from data in a spreadsheet, have you considered using PowerShell to accomplish this?

PWPS_DAB has Cmdlets that will do the tasks you mention, and of course Microsoft provides PowerShell Cmdlets to manipulate Excel.  Perhaps that approach might be a consideration for a solution to your requirements?

I invite you to have a look here: https://communities.bentley.com/products/programming/projectwise_programming/f/projectwise-programming---forum/197663/problem-using-the-projectwise-sdk-with-vba-in-microsoft-access

There you will find explanations about VBA and Excel code