CheckSpelling method won't spellcheck one cell

I'm new to this, but working on a VBA/Excel macro that has a button on a userform to spellcheck on a single cell. This is supposed to be a cross-platform excel macro (Mac- Excel v.X/PC 2001/2003). I'm developing on a Mac, and this line works fine on the mac:

ActiveCell.Offset(0, 5).CheckSpelling

but doesn't on the PC side of things. It continues to spellcheck the cells in the entire worksheet.

I've seen a suggestion along the lines of

Range("F2"[, "F2"]).CheckSpelling

So, since I'm not sure of the actual Cell Reference during execution, how can I "translate" the "ActiveCell.Offset(0, 5)" into an equivalent that will work in the second example that uses "Range(....).CheckSpelling.

Or if anyone has any suggestions other than the above, I'll try those.

Btw, in the VBA/Excel environment does MS fix stuff things like this, when the command works on one platform and not on the other?

Thanks