hello XLers

I think I'm missing something obvious here, but I could use some help.

I have code that, among other things, pastes formulas into cells. Part of
one of the formulas is:

FormulaStr9 = "=IF(OR .... more code here ... & INDEX(Sheet23!E:E,
MATCH(A8, Sheet23!A: A .....etc

All works well, but on other sheets I keep having to Replace Sheet23 with
Sheet24, Sheet 25, etc.

Now I have a variable called SheetName, but I can't get the syntax of the
formula to work when using it. How do I use SheetName in the formula? When
SheetName = Sheet23, the formula should give the same result as the one
shown above.

Much thanks for any help
anny