This expression G_G1 N05620 SOURCE VALUE { V(0, N05492)*{PWR((25/TEMP),1.11)} } should not give any error. If it is giving error, please check about following
Is node N05492 defined and not floating
make sure variable TEMP is defined, if you have very old version of PSpice you may get error for same, however this error would not appear in newer ones.
Share the error message so that once can suggest a solution.
This expression means V multiply (25/TEMP) to the power 1.11
Hope this is readable format.