How Does One Extend a Range to Include One Row of Data?

I have a range which has the address of one cell.

I would like to extend this range to include the row of data.

So that if rg.Address = $C$42

I want rg.Address = $A$42:$[last column which has data]$42, which in my case would be: $A$42:$I$42.

Help would be greatly appreciated!

Steven Craig Miller