Sheet(CaseName).Delete Error 13 type mismatch

[M Skabialka]

From Access:
CaseName = "Dallas"
xlApp.Run "ExtractData", CaseName

In Excel:
ExtractData(CaseName)

This gives me an error 13 - type mismatch:
Sheet(CaseName).Delete

But this doesn't:
Sheets("Dallas").Delete

I think
Sheet(CaseName) is looking for a number not a string. How do I convince it
otherwise?

Thanks,
Mich