File Upload on Visual Composer

Dear colleagues,

I need to build the functionality to do a File upload on Visual Composer. The user should be able to select a file from his local PC and upload it into a table or DSO.

I have created a function module that uses the function 'GUI_UPLOAD' to do the upload. If I execute the FM from transaction SE37 it works fine, selects the file and loads the data into the table. However, if I embed that FM into Visual Composer it does not work anymore.

Is it because it uses GUI technology that cannot be called from java environment of VC?

Anybody has a hint on how to solve this? Is there any standard functionality to do it?

Thanks,

Salvador Gimeno