Very similar questions were asked before in the discourse (see e.g. this, this, and this). Answers point to MathLink where one can plug an expression like this

using MathLink
sqx = W`Sqrt[x]`

and then evaluate this function like so

weval(sqx; x=2.0)
# 1.4142135623730951

I would like to define a normal Julia function like

f(x) = sqrt(x)

using sqx above. Is there a way to do that?

My end goal is to be able to take the string output from Mathematica and edit some of the variables to define such a function f(x).