In position of / In capacity of / In amount of / In total of

[Piak]

I sometimes see these phrases in some writings but I can not find them in any dictionaries. Are they correct or they have any meanings? Can I say:-
I am in the position of Maintenance Manager. (When I want to say that I work as Maintenance Manager. / I work in the position as Maintenance Manager. Or they have different meanings?)
I am in the capacity of Maintenance Manager. (When I want to say that I work as Maintenance Manager. / I work in the position as Maintenance Manager. Or they have any other meanings?)
I spent some money, in amount of 450 Dollars today. Can I say that?
I spent some money, in total of 450 Dollars today. Can I say that?

Best regards,
Piak

[RonBee]

I sometimes see these phrases in some writings but I can not find them in any dictionaries. Are they correct or they have any meanings? Can I say:-
I am in the position of Maintenance Manager. (When I want to say that I work as Maintenance Manager. / I work in the position as Maintenance Manager. Or they have different meanings?)
I am in the capacity of Maintenance Manager. (When I want to say that I work as Maintenance Manager. / I work in the position as Maintenance Manager. Or they have any other meanings?)

I would not use "I am in the position of" or "I am in the capacity of". What you can say is "My position is maintenance manager".

I spent some money, in amount of 450 Dollars today. Can I say that?
I spent some money, in total of 450 Dollars today. Can I say that?

The trouble with those sentences is that "today" is in the wrong place. (It is an adverb modifying spent.) Try: "I spent some money today, in the amount of 450 dollars." Or: "I spent some money today, a total of 450 dollars."

[Tdol]

What Ron said, or:
I spent some money, totalling 450 Dollars today.

This version is less common, but there are times when it could be used, especially if the items have been listed, for instance.

[Piak]

Your answers can now clarify me from those confusing phrases excellently. Thank you, Ronbee, Tdol and your forum teamwork as well. Your forum is the best for all who seek for language studies and very helpful to me too, indeed.

Best regards,
Piak.

[RonBee]

Thanks a bunch!

:D :D

[Tdol]

Thank you, and we're always ready to help.