Evaluating an algebraic expression introduced as strings

[#1]

I have a character column that has the duration of different processes in the following format:

3h 40min 15s

3h 47min 19s

5min 6s

29min

I changed this to another character column with find and replace:

3*3600 + 40*60 + 15

3*3600 + 47*60 + 19
5*60 + 6
29 * 60

How can I add a formula that evaluates each expression when the expression is a string?
This works:

Eval( Expr( 3*3600 + 40*60 + 15 ) )

But the formula doesn't as the expression is in characters:
Eval( Expr( "3*3600 + 40*60 + 15 "))

[#2 · Accepted solution]

Eval(Parse()) is what you would want to use in case like this

Eval(Parse("3*3600 + 40*60 + 15 ")); // 13215