You have a couple of problems but here is some of the relevant syntax along with the closest solution I can think of.

First, `wc=A1`

isn’t a formula. It is a string. A formula must begin with the equal sign. There is no reason for the digit to increment when you `fill down`

— the scripting command isn’t as flexible as the GUI. That command would work however if you fed it *only* a formula, like this:

```
tell application "Microsoft Excel"
with timeout of 1 second
set formula of range "B1" to "=A1"
fill down range "B1:B20"
end timeout
end tell
```

Each cell from B1:B20 would end up with a formula of `=A1`

through `=A20`

.

You could use the `autofill`

command and that may get you closer. Once you feed it two cells, it can sense a pattern and autofill the range.

```
tell application "Microsoft Excel"
with timeout of 1 second
set formula of range "A1" to "wc=A1"
set formula of range "A2" to "wc=A2"
autofill range "A1:A2" destination range "A1:A20"
end timeout
end tell
```

Each cell from A1:A20 would have a formula of `wc=A1`

through `wc=A20`

. But, since those are strings, this still isn’t what you want.

Your biggest issue is that it isn’t possible for cells to reference themselves (e.g. `set formula of range "A1" to "=A1"`

). You will quickly generate circular reference errors.

I would suggest putting the formula in column B instead, as in the first snippet above but with an addition to the formula like this:

```
tell application "Microsoft Excel"
with timeout of 1 second
set formula of range "B1" to "=CONCATENATE(\"wc\",A1)"
fill down range "B1:B20"
end timeout
end tell
```

You would end up with B1:B20 having the concatenation of “wc” and whatever value is in A1:20.

That all said, you could experiment with something like this:

```
tell application "Microsoft Excel"
with timeout of 1 second
set formula of range "A1" to "wc" & value of cell "A1"
set formula of range "A2" to "wc" & value of cell "A2"
autofill range "A1:A2" destination range "A1:A20"
end timeout
end tell
```

It’s a variation on two of the snippets above. It concatenates ‘wc’ and the *value* that’s in cells A1 and A2 and then fills down. The problem is that the results are not easily defined and depend upon what is in range A1:A2, not on what’s in the rest of column A. I would be surprised if it produced a useful outcome.