The "ă" is a common vowel in Swedish.
So, if you configure your computer to add the Swedish keyboard,
then you can hold-down the Windows keyboard key, and tap the space-bar to switch to the Swedish input method. Release the Windows key, and tap the key that is mapped to the "ă".
Repeat the Windows-spacebar to switch back to your primary language.
Or, when writing a document, insert one "ă" at the bottom of your document. Then, you can use copy-and-paste of that character into wherever place(s) you need it to appear.
Or, when typing into your document, just type some character that you otherwise would not use (tilde, back-quote, caret, ???) and continue keyboarding your entire document. At the end, use the "Replace" option within the "Edit" pull-down to change all of those "wrong" chărăcters to the "right" chæræcter.
"ă"