c.formula, get full formula text for external links

[kafisatz]

Hi

I am trying to extract the formula form a cell which links to an external file.
Is there any way that I can get the link of [1] in the example below?
I mean, I know which file it is, but I want to get the result programmatically.

julia> XLSX.openxlsx(oldfile, mode="r") do xf
           #val = XLSX.getdata(XLSX.getsheet(xf, "mySheet"), "E41") #419m 
           c = XLSX.getcell(XLSX.getsheet(xf, "mySheet"), "E41") 
           print(c.formula)
       end
+[1]BS!$W$9/1000000