I’m trying to find my way around Asana and want to know if you can open project Excel attachments in the desktop app instead of the browser. I know you can download then open, but then you would have to delete the attachment and reattach the updated spreadsheet.
Hi @Douglas_Theriot , welcome to the forum 
It sounds like you are attaching a local Excel file from your PC?
It would be better to store the Excel file in SharePoint or OneDrive and instead link to that file in Asana. Therefore, clicking on the attachment will open Excel 365 in your browser where you can make edits directly (along with other members, at the same time) which will be saved instantly & automatically.
The same also applies for Word docs and other supported files in Office 365. The other benefit is that the link in Asana will always link to the latest version of the file; no need to re-upload new versions.
You can attach links to files, in SharePoint or OneDrive, either from the task details in the top right…
…or within a comment:
@Richard_Sather , I have a question similar to Douglas that I hope you might be able to help with.
I have attached OneDrive/Sharepoint files to a number of my tasks. But I do not like working on Office 365 files in the browser and instead to prefer to work on these files in the desktop app. When I open the Office 365 files from Asana, it defaults to opening the file in the browser. Do you know if there is a way for set my default as opening in desktop app? I have done this for MS Teams and other programs, but could not seem to find an option for marking the desktop app for opening Office 365 files. If not, its not too much of a worry as I can always open in the desktop app from the browser view, but was just hoping to find a way to avoid the step of opening in browser first.
Hopefully, I communicated that clearly enough. Many, many thanks.
Hi @Nathan_Cogswell , that’s clear enough, thanks 
I’m not entirely sure to be honest but I’m sure these are settings outside of Asana, i.e. browser settings, such as default app to open certain links so it would depend on your browser.
Or it could be this, which I just found:
Open file links directly in Office desktop apps - Microsoft Support
Let us know if that works!
Thank you, @Richard_Sather. On the link you shared, I noticed this note “The following scenarios are not supported today, but these will continue to open in the web: . . . Opening links from other 1st party Microsoft 365 clients like OneNote, Skype, or Microsoft Teams. Or from 3rd party apps such as Slack, EverNote, etc.”
So Microsoft 365 might not yet support this functionality from links in Asana, but I will continue to explore the various settings outside Asana.
Will report back if I find the magic solution! Very grateful for your time and assistance.