>One of our table is named with 81500018.dbf. How can we select it using a variable. Assuming lcTable='81500018' and the table is open, the following won't work:
>
>SELECT(lcTable)
>
>As the first character is a digit, Visual FoxPro will try to select the area number instead and not use the table name.

I suppose the correct alias name should be [A], [B], [C]...
Try:

=Aused(UsedAlias)
For iX = 1 to Alen(UsedAlias)/2
  if [8150018] $ DBF(UsedAlias[iX,1])
    CorrectAliasName = UsedAlias[iX,1]
    Exit
  endif
ENDFOR

Of cos, I still advise you to avoid using digit as tablename because still many places need recode. change the name and then easy to maintain!