This works in VFP 6 SP5. You can use macro expansion.

example

M.lcMytagname = "TAG1"
m.lcIndexExpr = field(1)+" + "+field(2)
index on &lcIndexExpr tag &lcMytagname
?key()
?tag()

Or 

m.lcIndexexpr = "index on "+indxtable.expr+" tag "+indxtable.tagname
&lcIndexexpr
?key()
?tag()

or 

M.lcMytagname = "TAG1"
m.lcIndexExpr = field(1)
index on &lcIndexExpr tag (m.lcMytagname)
?key()
?tag()

*!* However the following does not seem to work as expected (though I thought it would)
*!* ?key() returns "(m.lcINdexExpr)"

M.lcMytagname = "TAG1"
m.lcIndexExpr = field(1)
index on (m.lcIndexExpr) tag (m.lcMytagname)
?key()
?tag()


 

HTH

>(VFP 7.0 SP1)
>
>Hi,
>
>I would like to create new index tags for tables using tag names and index expressions contained in a table.
>
>The INDEX command will not allow me to use a variable or field reference for the tag name or expression.
>
>Is there a way I can accomplish this?
>
>Thanks
>Gaylen Miller