variable virtual base (fasm)

Is it possible to make variable virtual base

for example

Code:

virtual at esp+espFix ; like define analog vs equ
        ofn OPENFILENAME
end virtual

...
espFix=0
...

espFix=espFix+4
mov     [ofn.hInstance],eax

it is not problem to add adder manualy.
Even more that could be achieved via macro
but may be there a way to got variable base to virtual in "out-of-the-box" way?

Code:

macro varvirtual definition& {
        match =at addr, definition \{
                macro @virtual@ name,def,val& \\{
                        local ..var
                        ..var def val
                        define name ..var+addr \\}

                macro endv \\{
                        purge label,@virtual@,endv
                        restruc db,du,dw,dp,dd,dt,dq
                        restruc rb,rw,rp,rd,rt,rq
                        end virtual \\}

                macro label def \\{ match . type,def> \\\{ @virtual@ .,label,<type \\\} \\}
                struc db [val] \\{ \common @virtual@ .,db,val \\}
                struc du [val] \\{ \common @virtual@ .,du,val \\}
                struc dw [val] \\{ \common @virtual@ .,dw,val \\}
                struc dp [val] \\{ \common @virtual@ .,dp,val \\}
                struc dd [val] \\{ \common @virtual@ .,dd,val \\}
                struc dt [val] \\{ \common @virtual@ .,dt,val \\}
                struc dq [val] \\{ \common @virtual@ .,dq,val \\}
                struc rb cnt \\{ @virtual@ .,rb cnt, \\}
                struc rw cnt \\{ @virtual@ .,rw cnt, \\}
                struc rp cnt \\{ @virtual@ .,rp cnt, \\}
                struc rd cnt \\{ @virtual@ .,rd cnt, \\}
                struc rt cnt \\{ @virtual@ .,rt cnt, \\}
                struc rq cnt \\{ @virtual@ .,rq cnt, \\}

                virtual at 0 \} }

test:

Code:

varvirtual at var
        A dd ?
endv


var = 0
db A dup 0 ; produce 0 bytes
var = var+3
db A dup 0 ; produce 3 bytes