A thought... I would not use WriteExpression, rather I would do somethinh like the following:

local aProp(1), aPem(1), i, oCol
if not file('SavePems')
    create table SavePems (cuser c(20),Pems m)
else
   use SavePems in 0
endif
locate for cUser == this.cuser
if not found('SavePems')
    append blank
    replace cUser with this.cUser
endif


dimension aProp(1)m aPem(1)
for i = 1 to aMembers(aPem,this.oGrid)
    if pemstatus(this.oGrid,aPem(i),1)    && Get the changed properties only
        dimension aProp(alen(aProp,1)+1)
        aProp(alen(aProp,1)) = 'this.oGrid.'+aPem(i)+'='+trans(eval('this.oGrid.'+aPem(i)))
    endif
endfor
for each oCol in this.oGrid
  for i = 1 to aMembers(aPem,oCol)
    if pemstatus(oCol,aPem(i),1)
      dimension aProp(alen(aProp,1)+1)
      aProp(alen(aProp,1)) = ;
        'this.oGrid.'+oCol.name+'.'+aPem(i)+'='+trans(eval('this.oGrid.'+ocol.name+'.'+apem(i)))
    endif
   endfor
endfor

save to Memo all like aProp
use in SavePems

Not tested you need to fill in the blanks, and figure out the restore.

Glenn