Dynamic MS Word Document Identification and Update: MS Forms - MS Word

[csantab3]

I've got a problem that is difficult to articulate. 

So, I have an MS form that clients will submit to me, this MS form creates a new folder, and automatically populates MS Word, which creates a copy of itself in the new folder. This all works great. 

However, these dynamically created files will need to be later updated by 2 separate forms in the future, so I need to automate a process wherein when a future form is submitted a flow will be triggered by said form that can first identify the dynamically created word document file, then update the corresponding content controls. 

I have no idea how to go about a solution for this. I've got a feeling if I create an Excel document (upgraded to sql later) then the submission ID from the first form can be taken a Unique id that is mandatory on all future forms, the same submission id that would act as the document name? that way the Flow could search through a folder looking for a document with the name the same as the ID submitted in the second form, then update the word documents content controls from there? but does anyone know how I'd do this?