David, this should be fixed in the next excel importer release. Until then you can make a small change in the module and you should be able to select the microflow.
If you would open the form ExcelImported.Column_NewEdit, and scroll down to the reference selector for the microflow.
My guess would be that you have objects checked in the option 'constraint by'. If you would go to the properties of the reference selector and uncheck all items in the property 'Constraint By', you should be able to select the microflow you want. Just keep the xpath constraint, that filters out the microflows that return nothing.
The other option would be to just type the exact name of the microflow into the text field. That should also allow you to pick the microflow you want.