Can you use a User Parameter for an ExcelReader and connect it to an AttributeManager transformer?

This should work. When you add a reader FME will auto generate a user parameter for the input path. 

In this case it’s “SourceDataset_XLSXR” but you can easily rename it to what ever you want.

Check that you have the prompt turned on otherwise you’ll not get prompted.
 

You’ll want to be careful with the sheet names and schema of your workbook - if you are just adding a reader and then pointing the file FME will expect that the repointed file have the same sheets/named ranges and schemas for each.

If you have different columns or sheet names then FME will miss them. There is a way to handle it but it’s another level

There is a little weirdness with FME Readers in that then you look at the readers properties it will always resolves the parameter to where it’s pointing so it looks like it’s not using the parameter when it is. If you swap your Reader with a FeatureReader transformer then the parameter will show.

 

For example here the FeatureReader shows the parameter name but the excel reader above shows “somefile” in the path (the value of the parameter).