Filling a row with values
:

Don't.  

People read code downwards much better than they read across.
Almost all code everywhere operates under the convention "(at most) 1 statement/operation per line". Colons : are small and very easily missed. Just stick subsequent operations on newlines and you'll avoid a lot of confusion/errors down the line.



Call is fully deprecated

It's not needed anymore and your code will run just fine without it. Assuming you name your methods well, dropping Call will also means your code reads better.

You will need to modify your calling syntax slightly though. When you have a DoThing Sub, this is valid syntax:

Call DoThing(Arg1, Arg2)


But this is not:

DoThing(Arg1, Arg2)


Functions get brackets. Subs do not. Like so:

Var = Function(Arg1, Arg2)
DoThing Arg1, Arg2




Don't let renaming break your code

Call Modul1.AutoFill(target)

Sheets("SourceSheet").Range("B" &amp; itemCell.row &amp; ":G" &amp; itemCell.row)


If that module gets renamed, or that sheet gets renamed, your code will break. 

Fortunately there are easy solutions.

1: Don't qualify your module references

You shouldn't need to specify which module your subs are in. If you do, this implies wider problems with your code. If your methods are descriptively named and you don't do something horrible like having 2 identically-named methods in different modules, just call your method using its signature. 

2: Sheets have Codenames

If you go to the properties window and select a Worksheet, there will be a (name) property. This is the sheet's Codename. By default, new sheets have codenames like Sheet1, Sheet2 etc. A Codename is effectively a global worksheet variable that always refers to that sheet.

So, assuming you give "SourceSheet" a Codename of sourceSheet then your code can simply be:

sourceSheet.Range("B" &amp; itemCell.row &amp; ":G" &amp; itemCell.row)


And now your users can name the sheets whatever they like and your code will still run fine.



Be Explicit with your naming

Your method names are OK, but very, very ambiguous. AutoFill, GrabStoredData, FillRowWith, they all imply a level of generality that is at odds with what they actually do.

As a rule, names should be descriptive, then unambiguous and only then concise. Easy-To-Understand trumps Shorter-Name every time.



GrabStoredData(itemName). Not a clue what that does in particular.  

GetRowRangeOfItemData(itemName). I immediately know exactly what that does. It's going to return a Range Object for a given item. This Range Object will be on a single row.



AutoFill(Cell). Fill What? Where? With what?  

FillItemDetailsToRightOfCell(Cell). Takes about 0.2 seconds longer to read. Takes much less time to understand. Especially when someone else (or you in 6 months time) is coming back to this code with no memory of the internal workings.



FillRowWith(Range, Cell). If I see that I'm going to assume it, well, fills a row. No Idea what those variables are, particularly. 

PasteRangeToRightOfCell(Range, Cell). Again, takes a fraction of a second longer to read, takes no time to understand exactly what's going on.