Depending on the contents of two cells, I would like to include in a formula
a different variable name (already defined). The problem is, I would like to
concatenate a given text together with the contents of those 2 cells to form
the name of a specific variable. I have looked for a function which could do
the trick (I mean, converting a string to a variable name), but apparently
there is not one.

Example: =Sum("Variable"&Q1&Q2)

If Q1 = "A" and Q2 = "5", the formula should hipothetically return the sum
of the cells referred by the variable named VariableA5. Unfortunately, it
shows a VALUE error.

Thanks in advance